Excogitation is a skill that on paper seems good and definitely would have seen use in HW, but with stance dancing no longer being a thing, Exocogitation seems superfluous, given its 60s cooldown while still costing aetherflow, to give us a maybe heal that's only slightly stronger than Lustrate, which you can use whenever you want and without cooldown

First off I would take away its aetherflow cost, since not everything needs to cost aetherflow. Having it with a cooldown and aetherflow cost is pretty dumb

Second, the fact that it only goes off when the target's health drops below 50% and can just drop off when the timer runs out hurts a lot. I feel it should take a page (hurr) from AST and copy Earthly Star. Apply the buff which you can activate for a heal whenever you want. Let it sit for a set amount of time and it gets enhanced, like having a higher potency or perhaps a stronger shield than Adlo. Maybe even let us deploy Excogitation so we can set this off on the entire party