Intro / playstyle
This is a build for end game content such as steel path. This build is extremely strong in solo but also provides massive utility to any team in the form of hp, shield, and energy restoration, armor stripping, damage buffing, crit chance buffing, and damage resistance. This is a very active build that requires a lot of attention to your ability durations, resources, and cooldowns.

Best Missions
The most effective place for this build is something like survival, but it is also very good at killing high strength targets like assassinations as long as the enemy is not immune to Link. In general, [Trinity] can struggle with protecting objects such as the defense point, mobile defense point, or keeping enemies away during interception missions, so avoid those mission types with this build unless you are in a support role.

Recommended weapons
Primary and secondary weapons with naturally high critical chance and damage.

Note about umbra mods
[Abating Link] requires 168% power strength to fully strip armor. I achieve this with [Umbral Intensify], [Umbral Vitality], and [Power Drift]. If you play with less than 168% power strength the build will be fine but link will not strip 100% of enemy armor.

Priorities
1. Cast Link as soon as the cooldown is over
2. Keep energy full with Energy Vampire
3. Keep buffs from blessing active at all times
4. Keep Roar buff active at all times

Skill usage

Roar
This is a good helminth option for [Trinity] since we already have a large duration and decent power strength. about 50% damage increase for 72 seconds. Try to cast this near team mates since it lasts a long time and can not be re-cast until it wears off. This is not a requirement for the build and you can play this build with Well of Life or a different helminth ability that you prefer.

Energy Vampire (EV)
Very self explanatory skill that [Trinity] is famous for. Since we have high duration and low range, the most effective way to use EV here is to cast it on a target near ourselves or a team mate and then immediately kill the target since EV releases all remaining waves of energy when the target dies. Worth noting that EV also stuns the target.

Link
Ignore the damage [Reflection] part, the real benefits of link are that you take 75% less damage, are immune to status effects and knockdowns, and you also remove 100% of the armor from 3 nearby enemies. [Abating Link] is what makes this build so strong in Steel path where armor values can be scaled very high. Keep this ability active AT ALL TIMES. [Abating Link] requires 168% power strength to remove 100% of enemy armor.

Blessing
[Trinity]'s panic button. If you died, you probably should have just pressed 4. Restores 100% of your shields and health, provides another 75% damage reduction. Use this ability in moments where you feel threatened, since it fully replenishes your HP and Shields, resetting your shield gate. thanks to [Champion's Blessing], increases [Trinity]'s primary and secondary weapons' critical chance. If you cast Blessing again before [Champion's Blessing] expires, the buff will be strengthened and the duration will be refreshed, so try to cast blessing before this buff wears off. Blessing affects allies within AFFINITY range not Ability range. Because of this it still has the normal range despite our low power range %. The Affinity range can be increased via Vazarin school if you wish. Blessing's 75% damage reduction applies to allies but [Champion's Blessing]'s crit bonuses do not.

Mod Explanation
[Combat Discipline] is useful because it is hard to consistently heal HP with Blessing to activate [Champion's Blessing] without the HP loss that comes with [Combat Discipline]. The heal for team mates is largely irrelevant. You could use a damage focused aura instead if you prefer such as [Rifle Amp] or [Steel Charge]. Avoid [Energy Siphon] and [Corrosive Projection] since you have other solutions for these.

[Umbral Vitality], [Umbral Intensify], and Power Drift let us surpass 168% power strength to fully strip armor with abating link.

Continuity, Narrow minded, Stretch- These 3 in combination give us massive duration for our buffs and [Stretch] helps mitigate the range loss from [Overextended] so that our EV is still usable. the low power range % is actually OK for other skills since blessing works off of affinity range and low range can sort of help link target things closer to you instead of random enemies that are far away.

Abating Link / [Champion's Blessing]
If you have to pick one then use [Abating Link]. [Champion's Blessing] doesn't help team mates and the armor reduction will be more impactful than the crit most of the time.

Other mods I considered:
Adaptation / Rolling Guard- This would really give you just an absolutely unnecessary amount of tankiness. I dropped Adaptation for Stretch in order to keep EV effective.
Umbral Fiber- This would remove the need for [Power Drift] since it increases Umbral Intensify, but i'm not even sure what other exilus mods trinity would benefit from
Quick Thinking- An older build for [Trinity], no longer necessary since blessing's damage reduction doesn't scale with HP healed. I dislike running this because if you get downed while using this you will have no energy for EV if someone picks you up.
Streamline- If you prefer casting EV less and don't mind having a smaller energy pool this could be an option instead of primed flow.
Natural Talent- [Trinity] casts a ton of abilities and they have substantial animations. I personally get my cast speed from Madurai focus but i have been tempted to run this in the past.

Arcanes
Flexible slot, use whatever you have available.