Notes

Jill's focus as a character is a tank. That means that she needs damage, but also needs to have a lot of defenses. I tend to prefer passive defenses (such as resists and regeneration) over active (such as clickies and heals). As such, you'll see the skill tree reflect that.

Shield/Hull Restoration are just too good to pass up. +25% Hull/Shield healing are a solid addition to any heals, especially since most heals don't have some "baked in" Cat1 healing like weapons do for damage. Now, this build may not have a lot in the way of specific heals, but everyone has access to the Undine shield bubble and Brace for Impact, so at a minimum it enhances those. Rally Point Marker, a power I typically use, has both hull and shield healing and as such, benefits from both points. My Kiwavi uses the Protomatter Field Projector, and its regen is enhanced by both skills.

Advanced Hull Capacity is not a typical choice, but I have at least two items on both the Kiwavi and Endeavour that scale with max hull. The Tilly 3pc lightning zap Mycelial Lightning scales its damage up to 200k hull, and Tyler's Duality reputation trait scales its CrtH up to 200k hull. This makes 200k hull the target hull I am for. Now, the first point is 15% more hull, then the next is 10.5%, and the last is 4.5%. This means that last point gives 1/3 the bonus the first point does, but in context, that is still 2,835 (Kiwavi) or 2,885 (Endeavour) extra hull. This also contributes to regen effectiveness. Regen heals 3% of hull in a specific increment. So, 4.5% capacity means an extra ~85 hull healed every tick of regen. That may not seem like a lot, but with 300% regen or so, that's a tick every 0.6s! In the 10 seconds Aux to SIF takes to cool down, that last point of Hull Capacity has healed 1,500 hull. (I'm not selling you on this, am I?)

I pick up a point in shield capacity, but generally don't rely on shields to stay alive. Reverse Shield Polarity doesn't rely on capacity, but it's an easy point to spend for some extra capacity the rest of the time.

Weapon Training adds a lot to my primary damage source, which is weapons. Energy weapons are what do the most damage, but the token Torpedo packs a punch as well with the extra damage from Projectile Weapon Training. I choose Improved because I choose to use that extra point elsewhere.

Since energy weapons are a primary damage source, EPS really helps keep my extra power topped up as weapons drain power when firing. These two points double the speed I get power restored.

Impulse Energy shunt is completely wasted, Miracle Worker primary means power moves instantly after Full Impulse and the "benefit" from the shunt is wasted.

Impulse Expertise, however, is something I always max out anymore. I tend to fly large ships, and they need all the help they can get in the speed and turn department. Impulse Expertise helps both.

I always pick up at least one point in both Control Expertise (CtrlX) and Drain Expertise (DrainX) not because of the buffs, but because of the resistances they offer. I also picked up the second point in CtrlX because I run several control powers for Unconventional Systems, and I run Fragment of AI Tech, which turns CtrlX into damage for my weapons.

I don't find Drain Infection useful on this build as I have no drains to enable it. I do pick up Control Amplification because I run controls, and the extra exotic debuff helps out my teammates.

Accuracy/Defense is a tough one to gauge, especially because you never know exactly how accurate you are. 100% accuracy is optimal, but extra accuracy is just turned into a little CrtX (CrtH & CrtD is CrtX). If you are missing in your parses, add some accuracy. If you have 100% accuracy, maybe spend that point elsewhere? Unless you start missing again... Defense is similar, and more complex because of movement adding to Defense. I pick up improved in both because... it feels right. I don't have a definitive answer.

Hull Plating is passive defense, but not quite as good as "all" damage resistance. Being a tank, one point here is well spent, though spending the next two for Kinetic and Energy resists is harder to justify, especially in a world with Honored Dead and History Will Remember which are huge boons to tank survivability. I sometimes skip this point on damage builds because 15 actual resistance is pretty small compared to some powers (Aux to SIF) or traits (Repair Crews), and some have way more than that (Terran Engines, 100; Honored Dead 10x20)

Shield Regeneration is special in some way, but you should read Jayiie's work for details on that. I always pick up a point here because its so special.

Shield Hardness is a point I rarely pick up, but being a tank, it seemed like a good idea. Basic Skills offer often as much or more than Improved and Advanced combined, so a single point can go further spread out than focused.

Speaking of focusing, Criticals' are always a crowd pleaser. Since most of my damage output here is based on weapons, I took all 3 points in both skills. I would say if a point is to be skipped, 0.4% CrtH is not much return for a skill point. If I didn't already have Advanced Hull Capacity, I'd evaluate if the point in Hull Capacity would be worth more (via Tyler's Duality) than the point here.

As far as Power goes, I'll cover all 9 unlocks at once. Subsystem tuning (and power in general) is a tricky subject. Each ship comes with power bonuses, and I am using Emergency Power abilities as well. I ended up choosing Warp Core Potential to add a flat 3 to each subsystem for a total of 12 (largest single +power per skill point). I also chose offensive because of the 4.8 power for engines trying to speed my ships up, and the 4.8 helps for my energy weapon output. This is a total of 9.6 power for the point. Improved Warp Core potential adds a total of 8 (2 per system), and adding to a specific system only adds 3.2 power, so significantly diminishing returns. Beyond weapon power, I don't end up needing a lot of extra power because of batteries and Emergency Power abilities.

Exotic Particle Generator (EPG) is an odd point here, but I think it has good value for the point, netting 50 EPG to boost any abilities that use EPG (such as clicky consoles). I wouldn't fault anyone for not choosing the point in EPG on a build where exotic powers aren't a primary damage source.

Long Range Targeting Sensors is always maxed out on energy builds for me because it is the only source that reduces damage falloff with distance. There's no other way to get this.

Hull/Shield Pen for weapons is a tough one because these skills translate to such a low amount of actual value, and they are only for weapons (not Kemocite or Mycelial Lightning, etc). Even though I am extremely focused on weapon damage, these are near the end of the list for pickups because the value is so low. A single point is 1/2 a [Pen] mod, and all 3 is a single [Pen] mod. My AP beams already have a [Pen] mod, but my Kiwavi doesn't have that, so it is helpful to pick up to at least Improved on both.

Readiness is absolutely wasted because of the methods I use to hit global cooldown. I primarily use Photonic Officer 1 (PO1), which manages cooldowns just fine 2/3rds of the time. Using Entwined Tactical Matricies (ETM) for Fire at Will/Torpedo Spread (FAW/TS) means I need to only take off 10 seconds of their 30 second initial cooldowns. Since I am running strategist and Threatening Stance on, I also get cooldowns from using heals when Photonic Officer is on cooldown. I'm also more likely to miss my FAW/TS timing due to not being able to fire a torpedo spread than missing cooldowns (more on that later).

Shield Mastery is always terrible. Ignoring a random hit once every 20 seconds is terrible, and none of the other points help either.

Coordination is really solid for me solo, but also as part of a team. None of my builds use hangar pets, but both have summon clickies (Delta Reinforcements, etc.). As part of a team, I can't expect anyone to send the buff my way if I don't send it theirs (Do unto others as you would have them do unto you, Matthew 7:12).

As far as unlocks go, there's usually either a pretty minor choice or only one relevant option. I don't push skill points anywhere just to hit unlocks. 

Unlocks

Since I have a balanced skill tree, I end up without an Ultimate, which is fine by me. Most unlocks are pretty straightforward.

Engineering-5 (Engineering unlock for 5 points) is between Hangar health for my pets, or doubling the duration of most batteries. I don't see 10% extra health really ever being worth choosing, but every build can take advantage of Battery Expertise, and this is the only place you can get it!

Engineering-10 is between hull capacity and subsystem offline resistance. I don't have a great number for subsystem offline duration, even moreso how the skill reduces this. Subsystem Repair is a skill called out in the bridge officer trait Leadership, which I tend to slot for their regeneration so I end up with this skill as a byproduct. 10 Hull Capacity isn't that impressive, but on a cruiser, I'll take it. This is 3% more hull, which makes regeneration that much more effective. Neither pick is impressive, so there isn't a definitive right answer. 

Engineering-15 and Engineering-20 are just +2 to specific subsystem power, so they aren't worth dead points in Engineering to chase. The Engineering Ultimate is also unimpressive single target. 

Science-5 is entirely a preference between sector speed increase or transwarp cooldown reduction. I tend to favor transwarp cooldown as most locations can be transwarped to anymore, especially endgame places like fleet holdings. 

Science-10 is between shield capacity and starship stealth. Since I am not relying on stealth (just the opposite), shield capacity makes the most sense. 

Science-15 and Science-20 are some pretty minor resists or perception. Control Expertise and Drain Expertise provide these skills naturally. The Science Ultimate is not helpful in the current state of the game as it would reduce my effective CrtH. Therefore, none of these are worth taking extra points to unlock. 

Tactical-5 is absolutely essential for a tank. Choosing 100% extra threat for Threatening Stance makes a large difference, whereas 10% extra damage for hangar pets won't make that large of a difference. If you made the wrong choice here, please respec. 

Tactical-10 and Tactical-15 are somewhat preferential, but I find that the CrtH just slightly edges out the CrtD. 

Tactical-20 is a super small choice, but since this is a tank, the extra defense was my choice. Not worth a respec if you choose accuracy. 

Notes

An addition to the game in 2020 was been Ba'ul Antiproton Weapons. These trade the innate Critical Severity of Antiproton for a reflection which deals 5% of damage dealt to target to the closest target. This applies to every shot, and with the lobi 2pc this is further increased to 10% of total damage dealt to up to two additional targets after the initial. There are some effects which carry over on these reflections, such as Suppression Barrage Debuffs which were present on the Endeavor version of this build.

With the Lobi Ba'ul weapon and console set, Linked Sentry, the reflections can be upgraded to deal 10% of damage to target and bounce to two targets. It also grants the basic reflection to standard Antiproton weapons. Because of how tanking works, Ba'ul weapons have quickly become the go-to for tanking options. This isn't to say that other weapon types are inherently bad, but the inability to hit as many targets that Ba'ul weapons can leave them lacking for ability to draw as many targets. Notice, however, that I did not fit out all of my weapons as Ba'ul beams, as I already had several crafted AP beams from when [Pen] weapons were the best. They each have [Pen] modifiers and a mix of CrtD/Dmg modifiers. Since they aren't Ba'ul, they will end up only reflecting to one additional target instead of two, but there is quite a bit of cost to pick up more Ba'ul beams and fully upgrade them simply to hit another target. 

I've even experimented with weapons from the Nukara reputation. While these do have a chance of bouncing, and even the reputation set one always bounces, they are nowhere near as strong as Ba'ul AP. I could slot the AP Nukara DDB, but since I am always in a firing mode, I would need all 3 pieces for the bounce to even happen since the reflections only happen when under standard fire or with the full 3pc set for Fire at Will. I did some limited testing, and the reflections were once per firing cycle (which under FAW is 5 shots), and on the order of 100-200 damage. Compare that to a Ba'ul reflection's 500-1000 and refracting with nearly every shot as long as another target is nearby, making a Ba'ul refraction 25x as effective as a Nukara refraction. 

As a note to any prospective tank players, feel free to choose whatever type you want. Ba'ul is great at tanking but there are better DPS options than can create similar threat. Crafted AP is 'cheaper', piezoelectric from Lukari Reputation, Phasers or Disruptors of any kind, and so on. Refer to the Energy Basics for some top contenders in each energy flavor. 

Since we are basing our FAW uptime on the trait Entwined Tactical Matrices, we need to make sure we have a torpedo to clear the Torpedo Spread, otherwise we will have to wait out the full 30 second duration and gain nothing from ETM. In this case, I chose the Dark Matter torpedo for its DoT application (for Entropic Rider, more on that later) as well as the 2pc set with the Lorca console. This set provides a large amount of CrtD to the build, and both the console and torpedo are very good. 

Notes

A newer setup is to use Temporal Specialization and Fek-ihri Torment Engine in order to get a really large DoT on enemy ships to lock in some threat. It's been near the top of my recent parses. The Temporal Specialization has Entropic Rider which is a 2.5% chance to create a DoT, and with as many Ba'ul Refractions and FAW bounces, of around 2,000 beam hits and 2,000 refraction hits, there were 500 Entropic rider ticks, which just helps lock in the damage. Not to mention, any of those targets that have a DoT of any kind will also have a -DRR applied from Atrophied Defenses. 

Also of note is the Tilly 3pc. The Mycelial Lightning is a great way to "lock in" your threat with a big burst of damage. Even a tickle from the Ba'ul beams and they get zapped with the 3pc. In theory, a Ba'ul refraction can be a tiny bit of damage, but has a chance to trigger the Entropic Rider, Torment Engine, and Mycelial Lightning. This really extends the coverage of the tank. Even without refractions, Torpedo Spread and Fire at Will both hit many targets in a short period of time, once again triggering these initial spikes of damage. Mycelial Lightning also gives us a little payoff for having a high hull capacity (up to 200k) as this scales the damage. 

Since we have the 3pc Tilly for the 3pc set, we really just need to pick what piece we don't want in the Tilly set. In fact, there's nothing wrong with going the full 4pc set and is a great budget option. For extra CrtH and CrtD, the Colony Protomatter Deflector makes a solid option. If you need more maneuverability, you could pull the Tilly Engine for the Competitive Engine. 

Bridge Officer Power Selection is something that has the largest swing in any build. If you don't pick your BOff powers correctly (and drag them to tray), you won't do anything. Each one of these has been hand-picked to interact with every aspect of the build for maximum performance. You'll see no duplicates here, cooldowns are managed so that maximum uptime is achieved with one copy of each power. There's not room for more than one!

Just about all of these BOffs have Leadership, which helps slightly with Hull Regeneration. Pirate is slotted since it is a free Bridge Officer with passive extra damage. 

Commander Engineering/Miracle Worker

The Lexington has one Universal seat, and we'd prefer not to use it for Engineering seats if we don't have to. As such, we cram a lot of engineering powers in here over the often higher- damage potential Miracle Worker powers. Ironically, most Miracle Worker powers aren't amazing heals, especially when compared to Reverse Shield Polarity and Aux to SIF. Most tanks benefit from either Suppression Barrage III or Reverse Shield Polarity III. Since we have a Commander Engineering seat and no Command seating, I went with RSP III. With enough skills and the extension duty officer, this is nearly 30s of damage being converted to shields. Best used as shield healing in trouble, it's long enough to use when you know you are about to take a lot of damage. 

The next slots are a little circumstantial. I had Construction Shuttle Wing III as part of an experiment, and it's a strong, sustained heal. By contrast, Aux to SIF II would also slot here and is a strong burst heal that is up very often. I wouldn't shell out for CSW as it can be pricey, but I already had it for other reasons, so why not give it a chance to shine. It's not used very often. 

Emergency Power to Weapons and Engines are the last two slots, and could certainly be used at higher ranks depending on your priorities. For energy weapons and Emergency Weapon Cycle, EPTW is required at some level. The ECH DOff is also great for maneuverability and requires EPTE. As such, I wanted more damage than maneuverability so I put them in EPTW II and EPTE I, but there's no reason you could change up the ranks of CSW/A2SIF/EPTW/EPTE based on your flying style. 

Lt. Commander Tactical & Lieutenant Tactical/Intelligence

We have two tactical seats, one of which shares space with Intelligence Specialization. The ranks of these powers, like the engineering powers, can be swapped around based on your preference. Kemocite Laced Weaponry (KLW) is a strong AoE -DRR that can hit a lot of targets with our FAW and Torpedo Spread. Also it mysteriously triggers on each DoT of Dark Matter Dissolution from the torpedo we chose. Higher ranks don't significantly impact damage as we aren't strong in exotics, but we do get more -DRR with each hit. 

Attack Pattern Beta is a solid -DRR debuff as well that we spread around with all of our FAW attacks. Now, you might wonder why we don't slot Attack Pattern Delta, which applies -DRR based on being attacked. The biggest reason is that the uptime of APB is nearly 100%, while APD is only around 50%. We do pick up a passive APD from a very optional Borg duty officer, but that's more of a nice to have than key to the build. 

Fire at Will and Torpedo Spread are the key to keeping threat as they hit many targets at once. Both are required with ETM to keep 100% uptime on FAW and keep our weapons hitting as many targets as we can. FAW is probably the only one I wouldn't use a higher rank on as we aren't so much after extra damage, which higher ranks afford. Torpedo Spread at higher ranks does hit additional targets. KLW and APB increase the -DRR they apply at higher ranks. APB is the only one of our four tactical powers that can't be slotted at Ensign, but only LtC. and above. 

I saved one slot for Ionic Turbulence, an intel power. This is a strong -DRR that applies in AoE and beats out any other powers we could slot in a tac slot. 

Lt. Commander Science (Universal) & Ensign Science

Our universal seat we dedicate to science, since all of our bases are covered with our tactical and engineering powers. The LtC seat does let us bring a utility Gravity Well which can be used to pull together a few ships as well as pull some threat in AoE. With Unconventional Systems, we also get a little Universal Console cooldown from it. We can't slot it any higher rank than rank 1, so that locks down this seat. 

Next, for cooldowns, we are relying on The Boimler Effect. However, this is a chance-based cooldown scheme, so it is best to have a reliable foundation to the cooldowns. Photonic Officer has a 66% uptime and is a solid cooldown on its own. This helps keep Boimler running effectively and is sufficient to cool down FAW to its global most of the time. Again, we can't slot any higher at the Lt. seat, so we take rank 1. 

Hazard Emitters is a solid, consistent heal and damage resist, as well as a good cleanse with no real equal. Tractor Beam fills out the roster as an Unconventional Systems trigger, as Jam Sensors works against us in resetting threat on a target after our initial burst of damage would have it targeting us. 

Miscellaneous