Trinity as a frame has multiple paradigms of use, but will, with few exceptions, be primarily in a supporting role. In this build the focus will be on maintaining three main resources for the team, Overshields, Health, and Energy. The effectiveness of maintaining these to increase survivability team wide can be further amplified by things such as armor and quick thinking, but that falls outside the scope of the trinity itself. It is important to note that this build is different than the more common energy vampire trinity builds due to the modifications included to support vampire leech.
The two main skills on trinity that you will be occupied with on this build are energy vampire (EV) and blessing. Well of Life is best used as emergency crowd control when EV is on cool down, or to heal a low health target to get one more EV out of them, or to amplify the EV damage due to it being based on % max health when initially cast. All three are niche use cases and for the most part could be completely ignored to no detriment. Link has the duration reduced so severely with this build that its use is limited to reactionary casts before a major influx of damage or crowd control, to guarantee a blessing to go off uninterrupted such as when utilized in a 2>3>4 rotation when your team is under severe load.
EV has some very unique aspects as an ability in warframe, and some mod interactions that are counter-intuitive. By default at rank three EV will restore 100 energy over 9 seconds in 4 pulses of 25 energy with a casting cost of 50 energy initially. Skills that utilize ticks in warframe have a frequency inversely proportional to skill duration. In practice this means that increasing the duration of EV would cause you to generate less energy per second on average, whereas decreasing the duration generates more energy per second. In addition, the fact that EV returns 100 energy with a base cost of 50 means that blind rage will always lead to a net gain for the trinity.
Blessing is a skill that has two components to it, a heal and damage mitigation contingent on the heal. By default at rank 3 it is an 80% heal with damage resistance for 10 seconds afterwards with a cost of 100 energy, but with 125% or more power strength blessing will fully restore all health and shields. It is important to note that blessing does not grant knockdown immunity, so casting link to cover a blessing cast is an important tactic when pressured.
This build requires extensive forma'ing of the frame in order to function, requiring 3 formae if the 10 rank mods are rank 8 or less, and 4 forma if the mods are maxed. This is as an end game trinity build. it requires the aura slot formad to dash, and 3 blank slots to be formad to dash, dash, V. Click the picture on right for further clarification.
Corrosive Projection - Trinity as a frame has no need for rejuvenation or energy siphon except in specific cases such as trying to counter some sort of energy drain mechanic, corrosive tends to be a greater increase in damage than weapon amp auras as well as being universal, and most other auras are niche utility uses if that with the only other major mentions being shield disruption for corpus (unless you have a mag) and energy siphon for infested.
Redirection - With the exception of very niche builds I always run either redirection or vitality. In this case, due to the 15 armor trinity has equating to only 5% damage mitigation, shielding is more useful for preventing instant death if you run guardian or protect. In addition as personal preference a low health pool makes me pay more attention to my teams health totals, but what mod you run is completely personal preference. If they release a primed version of trinity with 100 armor as seems to be the trend, the 25% total damage mitigation will likely make vitality a better choice.
Flow - Due to aspects of the build which will be expanded on later, you effectively have no efficiency in this build. This means that you require as large an energy pool as possible to handle the volatility from full cost abilities and massive energy restoration. In addition, this large energy pool synergises with quick thinking as well to increase survivability.
Quick Thinking - Increases survivability by draining 1 energy every 2.4 damage you take after reduction to your hp when below 3 hp until you run out of energy. with a max ranked prime flow on trinity this grants you an astounding 1,486 bonus hp that you can restore rapidly with EV, as well as give about half a second of 99% damage mitigation off of the reactive blessing you cast when you took this spike of damage. The two main drawbacks of this is that first you stumble when quick thinking activates, which can get you killed by interrupting other actions such as blessing, and second that if you do go down and get picked back up you will have no energy in your pool and will need to restore energy via other means before you can resume sustaining yourself with EV.
Overextended - The purpose of this build is to act as a team wide support frame, and to do that you need as much range as you can get. This mod gives twice the range of stretch, but at a massive hit to power strength which requires some modding to mitigate.
Transient Fortitude - This is the first place where interaction with reducing power duration is seen. As explained earlier, it makes EV return more energy over a given period of time, and the 55% power strength it adds almost completely mitigates the hit from overextended.
Fleeting Expertise - Continuing on with the duration hits, this combines with transient to get the 13% duration which this build is based on. In addition, the 60% power efficiency prevents blind rage from making things too unmanageable, such as causing EV to cost more than your starting energy total.
Blind Rage - Granting an astonishing 99% power strength with the hefty side effect of increasing costs by 55%, blind rage is what anchors this build as still having enough functional power strength to restore energy rapidly on a few vamps and make vampire leech useful. Due to increasing power strength more than the efficiency hit, it will always increase the energy returns on EV.
Vampire Leech - The capstone and original inspiration that started this optimization. With all mods maxed this will cause each EV to restore 291 shielding on targets with full energy pools, with the ability to grant overshield. This means that you can hit the overshield cap of 1,200 for your whole party off one target in 6 seconds with usage of Well of Life. In addition it allows you allows you to get a rough understanding of who might be in need of EV more than others with the overshield only being granted when energy pools are full. This can be replaced with stretch for use cases where you need to reach as many people as possible with EV or something keeps people spread apart, such as the buttons in part two of the law of retribution, or natural talent if you plan on running something where you expect to be performing a 2>3>4 skill rotation and key members have quick thinking.
Always make sure the first ability you cast is EV, if you run out of energy you are a frame with no skills and poor base stats. Always cast EV first.
This is an incredibly focus intensive build, and will require you to almost constantly be active with your abilities and aware of your team's status. Due to blessing costing 95 energy and the build lacking natural talent, your main goal should be to maintain a maxed overshield at all times to give you a larger window of time to react to a damage spike as well as prevent the need to cast blessing to keep people topped off from minor damage to health pools.
In addition, due to the massively reduced duration on EV, you can actually use it to outright instakill high value targets. Target something nasty, such as a corrupted heavy gunner, and cast Well of Life on them. This will increase their health pool by x10 and fully heal them, as well as preventing them from performing actions and lifting them up making them an easier target. Wait for the Well of life to run until it has 0.7 seconds on the duration, and then cast EV, which will finish casting as well ends. Due to energy vamp dealing 6.25% of the targets max hp as damage, calculated when first applied, this means that it will tick for 62.5% of their hp every 0.3 seconds four times.And due to this being % max hp, it doesn't matter what level the enemy is, they will die in 2 seconds of glorious glowing crowd control if executed correctly.
As mentioned previously, your link duration is severely limited and I have found three primary uses so far. First as mentioned earlier, it can be used to cover a blessing cast and guarantee it won't be interrupted. Second you can use it to mitigate a massive spike of damage or crowd control you see approaching, such as an infested ancient grapple or bombard rocket, and last, it has a use in stabilizing the frame and allowing you to cast EV>link>blessing continuously to give very small windows where you can be crowd controlled or spiked. This last case is where I use it the most, but if you expect to be doing this more frequently than some crazy last ditch effort to keep the team up, you might want to go with a different build.
So in general, start by hitting anything you can see with EV till your whole team has a max overshield, then work on assassinating high priority targets with Well/EV and keeping an eye out for when to blessing.
So why this build?
This is for when you need an energy vamp trinity that will also take some of the strain off of the need for constant blessings. The original inspiration was the vampire leech mod, but as my ghost clan started gearing into trials and we could only field 4 people on a good day, it became apparent that a second trinity to blessing would be a luxury we couldn't afford, even on nightmare. I can say with certainty that this trinity build will do its job and support the team even if four-manning nightmare trials.
This isn't to say that a blessing or crusader trinity isn't sometimes the better choice. I default to this as my go-to trinity build since it tends to give everyone the energy they need and enough tankiness to let the other support, such as a frost, use thier skills to prevent the team from going down. If you are going to need to spam blessing, you might be better off looking elsewhere.
But when executed well, when you are running across the battlefield executing enemies that give even your nova with a 5 forma penta trouble in a matter of moments, all the while ensuring that the team is overflowing with everything they could want to keep them fighting, you might find yourself seeing trinity in a different light.
Feel free to comment, questions and advice are always welcome.