These are the possible Perks

Squaddie
MZClotting - using abilities with HP costs grants a small barrier.

Corporal
MZFalseLife - consume HP to gain blood barrier

Sergeant, Major
MZHematicRites - consume HP to grant multiple allies blood barriers. scales with psi.
MZImpendingDoom - consume HP to curse target. explodes next time they're attacked.
MZRubyCurtain - consume HP to grant an ally a blood barrier. scales with psi.
MZBloodPillar - consume HP to create full cover

Lieutenant, Captain, Colonel
MZCoagulation - blood barriers heal for a portion of the remaining sheild when they expire.
MZLifeBalancer - balance your HP with the target. can be used to steal hp or heal allies.
MZCirculation - using abilities with HP costs grants health regen
MZBloodiedShroud - increased HP, faster wound recovery.
MZFleshOfMyFlesh - consume HP to revive a bleeding out target.

Brigadier
MZDropByDrop - reduces HP costs