U.S.S. Yi Sun-sin

Legendary Avenger Battlecruiser

Build Overview and Focus

Last Updated December 2023

When I started playing STO, the Arbiter was my first T6 ship. Normally R&D promotional ships are far outside of my budget, but since Cryptic gave one away in 2021, the Inquiry is essentially an upgrade to the Arbiter. For a more affordable setup, please see my build for that ship. At the time I first started building, Fire at Will was the predominant firing mode for energy builds, but even after that was nerfed, I decided to keep FAW on the build. I used this ship for flying story missions on Elite, and having the ability to defeat numerous smaller enemies like Tholian webs, Iconian probes, and Hur'q along with having a tankier build was attractive to me for my main captain who plays all of the missions. The choice of beams and torpedoes was chosen for immersion purposes to keep the ship more in line with canon representations of the TNG-VOY-DS9 era. 

FAW DPS builds are pretty rare, but this ship has been able to handle story missions fairly well (where you can expect more incoming fire) as well as a variety of Elite TFOs. The goal of this build has truly been realized in making the "toughest, fastest ship" in Starfleet that also packs quite a wallop. 

Platform selection

With Commander Engineering and one of the better specialization seats for energy damage (Intelligence), as well as five fore weapons and a must-have starship trait for energy builds, the Arbiter is a great candidate for a ship to make a tough off-tank that still puts out plenty of damage while being maneuverable. The Inquiry takes that as a starting point, and cranks it up to 11 by adding full-spec Miracle Worker to the package. The Arbiter was already a solid platform, but the Inquiry takes the same basic ship and design concepts and gives it a higher ceiling through the extra console, power, and specialization abilities, so it was a natural choice for me to select that as an Event Campaign reward for my first/main character and unlock more of its potential. From the Inquiry, the Legendary Avenger/Inquiry is a side-grade, trading the potential for 1 more engineering console (Isomag) against significantly better maneuverability. Since I wasn't running maximum Isomags on my build, this ended up being a straight upgrade and a natural transition, plus it came with an excellent ship trait. 

Flavor/Theme Choices


Yi Sun-sin was a legendary Korean admiral known for his innovative approaches to naval combat and victories against staggering odds in the 16th century. His decisive strategies defended his nation and earned him renown despite the distrust of the feckless ruling government. Nevertheless, his legacy endures as one of Earth’s greatest maritime leaders. The U.S.S. Yi Sun-sin has emerged victorious from multiple battles against staggering odds, including a Klingon Civil War a host of renegade Excalbian simulacrums, and a Terran incursion. I have dubbed this ship the Yi Sun-sin-B, since there was a canon Ross-class in Season 3 of Star Trek: Picard, the original Inquiry would have been the -A and now the Legendary is the -B. 

Meta Analysis

Budget Analysis

Using the EZRA rubric, this build would cost 628 USD to replicate. That is far more than what I spent on STO to make it. If the cost looks daunting, don't worry! Lower-budget alternatives are provided below.

Change History

Build Focus

This build combines energy DPS with survivability. There are some small contributions from projectiles and other supportive concepts as well, but those are tertiary.


Skill Unlocks


This ship is a classic beams + 1 torpedo set up. It has absolutely zero investment into exotic damage, so I am not skilled at all into those.

Intel/Strategist is the best-in-slot choice for non-tank Energy builds. Intel provides substantial damage through flanking and Intel Fleet. Strategist likewise adds damage through Logistical Support, Maneuver Warfare, and Show of Force, as well as some damage reduction through Layered Defenses.


Starship Weapons


Torpedoes: One, I wanted a torpedo for immersion purposes. Two, the right torpedo, when used with Entwined Tactical Matrices and Super Charged Weapons, is NOT a DPS loss compared to beam arrays. I was already going to slot the Quantum Phase Converter console, so adding the torpedo for its two-piece is an excellent DPS boost. It outparses most of my beams except the Terran/Disco. I could have slotted the Dark Matter torpedo, but I already had the Quantum Phase gilded and it doesn't quite do the same damage. Note that if you don't like the Disco DBB, but you are okay with the Dark Matter torpedo, I would use the DM torpedo in order to keep the 2-piece bonus. 

Mixing in 2 DBBs: Despite "don't mix weapons" being conventional wisdom for good reason, I've chosen to mix in the Wide-Angle DBB. For one, I wanted the two-piece bonus without the torpedo. For two, specifically on a FAW build with a torpedo and 2 Omnis, most of my weapons are hitting my forward arc anyway, with just one beam in the aft that can't fire forward. With 100% FAW uptime and at least 1 target in my side or rear arc, I'm firing that beam pretty much all the time anyway. Suffice to say, with this specific build (FAW) and decent piloting, I'm not really losing uptime on either my torp, my aft non-Omni beam, or my WADBB. The Pulse Phaser 

Firing Order

Starship Equipment


Drive Train: I've finally moved away from the Iconian 3-piece since in our current ISE/HSE runs, I can get it from teammates flying support. This combination yields slightly better selfish DPS if the 3-piece isn't being provided from a teammate, and is significantly better if it is. If I wanted more survivability, I would swap the engines for the Disco Engines to pick up the regeneration from the two-piece.  In terms of healing, the Yi Sun-sin is pretty tanky for a DPS ship and it's pretty rare to die in any Advanced TFO that doesn't involve killing yourself (i.e. Feedback Pulse, Voth damage reflection) which the Disco 2-piece regen won't help with.The ship is designed to be self-sufficient. It's not a full tank (though I've built one on the same character using most of the same pieces), but that only really matters for Elite runs. 

Starship Consoles

Set Bonuses


Isomags versus Locators: The new Advanced Isomagnetic Plasma Distribution Manifold Engineering consoles have been shown by analysis to be about 7.5% better than Vulnerability Locators for this build. They're either expensive on the Exchange (especially in Phaser flavor) or you'll need to farm approximately 21 of the appropriate Elite TFOs depending on how good your luck is, then re-engineer to Phaser (not trivial given their large mod pool) and upgrade them. If that's too much effort, slot Locators and play musical chairs with the consoles. Slotting the full 7 Isomags probably would have been better than some of the other consoles I have, but they were themed choices.

No Trilithium Set: The Gamma Omni is slotted over the Trilithium Omni set. According to both the Energy Weapon Calculator and several ISA parses, the Gamma set ends up being superior once you adjust the haste for uptime. There are a few reasons for this. 1) The Trilithium-Omni cannot be re-engineered and with FAW, the forced [Acc] and [Ac/Dmg] mods essentially costs me 2 mods since FAW does not benefit from accuracy overflow. It also doesn't have the 2% bonus damage from T6 reputations that the Inhibiting beam does. 2) The 10% weapon haste is great but it would require the console, and especially on a FAW build, does not proc often enough, whereas the -10 DRR from the Gamma beam is easily proc'd against big targets as long as you're not sitting completely still. Seriously, the haste proc has 2% uptime on a FAW build. 

Alternate energy types: Obviously all weapons would need to be replaced. Replace the Quantum Phase torpedo with Dark Matter Torpedo. If Disruptor, consider the Nausicaan Energy Torpedo. Quantum Phase Converter (unless Polaron) is the two console to replace. Keep D.O.M.I.N.O. and replace the Advanced Engineering consoles with the appropriate flavor.

VADA/Deadly Maneuvers 2-piece: This doesn't get slotted a lot for good reason. That said, I was already using the Ablative Hazard Shielding for flavor and survivability, so when I did the numbers, adding the VADA for its innate 15% Phaser damage and then another 15% Weapon damage from the 2-piece and the active's damage was better than the Altamid-Modified Swarm Processor, which is what I had there previously. That console has too much value tied into Accuracy which is wasted on Fire at Will since it doesn't benefit from Accuracy Overflow. 

Meta-Focused Tweaks:

If going full DPS with unlimited budget, you’re not using beams. That said, for higher damage at higher cost:

Budget Tweaks:

 If low budget, the Arbiter build is probably what you want, but anyway...

Bridge Officers

Meta Notes


Personal Traits

Meta-Focused Tweaks:

If going full DPS, with unlimited budget 

Budget Tweaks:

 If low budget, (try and keep the ones at the bottom) 

Starship Traits

Meta-Focused Tweaks:

If going full DPS with unlimited budget 

Budget Tweaks:

 If low budget, (try and keep the ones at the bottom) 


Improved Critical Systems was better than Promise of Ferocity on this build but not as good as Heart of Sol. Both were superseded by Universal Designs when paired with the Immolating Phaser Lance.

Reputation Traits

Active Reputation

Duty Officers

Meta-Focused Tweaks:

If going full DPS with unlimited budget, 

Budget Tweaks:

 If low budget



This ship manages cooldowns via Photonic Storm (Photonic Officer I, Calm Before the Storm and a little extra in readiness skills, plus a Krenim).

On an Inquiry, I don't really want to dedicate two of my engineering slots to A2B,nor do I wish to give up the universal seat for science to pick up Photonic Officer II . Nor do I want to double abilities or give up the bulk of my duty officer slots in a Drake/Dragon setup. This allows me to maintain high Aux power (for heals, the Aux Config Offense trait, and general defense) while freeing up duty officers to enhance damage. It's also easy to fly--the only things I need to do are constantly cycle my Tactical and Engineering chains, which I should be doing anyway. I could use Attrition Warfare for engineering abilities, but that's less forgiving unless Threatening Stance is on all the time. Despite having more survivability, this build is not a tank; plus Strategist has a number of damage abilities that would be lost if Threatening Stance was used constantly.

The chosen option syncs my tactical chain up with FAW, and since I am using Entwined Tactical Matrices to keep Fire at Will up all the time, I am not as concerned with dropping Kemocite/Attack Pattern Beta/Torpedo Spread to minimum cooldowns, as syncing them with FAW III is sufficient. Note that I do not even need Calm Before the Storm to get the desired cooldown reduction, but when it is active, it will help lower those tactical powers. Even in the worst case scenario where PO starts its 10 second downtime and no Calm Before the Storm right as my tactical chain is fired, I still have plenty of cooldown reduction to support a 20 second tactical chain. Boimler Effect is not needed either; with the exception of Narrow Sensor Bands all the powers are where they need to be. The graph above does not show the effects of Calm Before the Storm.

Link to CDR sheet for this build 

Ship Stats


With as many abilities and synergizing concepts as this ship employs, an efficient control scheme is essential. There are many ways to set up such a ship, so I don't pretend to assume that my way is superior. It works for me, especially with my background in RTS and MOBA games, where pushing many different keys quickly is essential. That said, I reduce the complexity somewhat to make it easier to fly.


I start with basic combos for the first 3 cubes. In an ISE run, I will use all of my longer cooldown buffs in the first fight as well as VADA, Tachyon Net Drones, and DOMINO, but not on ISA. Trigger Evasive Maneuvers to fly over to the left transformer and fire off all major abilities while at 1/4 impulse or stopped within 2 km of the transformer. FAW should take care of most targets. Once 2-3 of the generators are down, target the transformer with Focused Frenzy and Fire On My Mark. Be careful in timing EPtE here, as you'll need it to reset your Evasive Maneuvers. Ideally you activate EPtE here to reset the cooldown on Evasive and it's still active to fly to the right. I rotate to face inward toward the gate. 

When the transformer is less than 5%, fly towards the ball of spheres and give them a torpedo spread and cycle or two of firing. Once they start thinning out, Evasive Maneuvers again with Deuterium (reset due to Emergency Power to Engines) and head to the right side. Rinse and repeat, then Evasive Maneuvers again to fly between the Tactical Cube and Gateway. Some clever angling will keep the torpedo/DBBs firing as well as the aft beams. Make sure to flank the Tactical Cube. Frenzy and Fire On My Mark should be available here again. If it's ISA, this is where you use DOMINO and VADA. On ISE, a slower run might have VADA at gateway, but Tactical Cube is more likely. Lastly, don't forget to summon your Delta Alliance Beacon/Nimbus Pirates. In an average ISE run, I can get two off: one at the start and one at the end.

The importance of Crit and Flanking cannot be oversold. I saw significant increases in DPS from boosting Crit in doffs and traits. On my record runs, my weapons were parsing between 80-90% with roughly 40% flank percentage. There are players with better gear and piloting skills than I who've achieved much, much higher percentages, but I will say broadly that when in doubt, add crit. Since flanking includes extra crit chance/severity with Intel, you can't go wrong with flanking either! Look for the downward pointing arrow on your target. 

Parse Breakdown

Numbers from record ISE

Weapon crits were around 70-80%. This has gone down due to swapping Locators for Isomags; flank rate was around 40% averaged across weapons. The team composition for this run was this ship, a support tank, and three supports.


Only a handful of ships support both Intel and Miracle Worker seating and they are all expensive with one notable exception: the Terran Lexington. If I had to fly the Lexington, I'd switch from Photonic Officer to A2B with 1 instance and Boimler because otherwise you'd need to fill those extra seats with Controls to trigger Unconventional Systems, which gets expensive fast. That said, Jay covers that amply here. The other ship that could seamless port this build is the original Inquiry Battlecruiser, which is what I was flying prior to acquiring the Legendary version. The original Inquiry gains an additional Engineering console slot (replacing a tactical) compared to much higher turn rate on the Legendary. Since I'm not running full Isomags, I preferred the Legendary one. The Jovian Intel Raider would have to drop Reverse Shield Polarity altogether or else pick up excessive Engineering seating and has a substantially different weapons layout. The Legendary D7 Intel Battlecruiser, on the other hand, would have no issues porting this build over.  Lastly, the Vaadwaur Juggernaut would struggle without Prevailing Engines due to its sluggishness, and would also need to drop Reverse Shield Polarity or Auxiliary to Structural.