For the Warrior (?) class there should be a hunker mode where you are given a span of 3 (or more) turns and a source forcefield covers you and gradually heals you over those 3 turns. Depending on the level of intelligence and actual level you are on it determines the amount of healing you receive.

Almost like a healers regen, but personalized. And if you want to get crazy let him hunker one of his teammates that are in trouble.

Not sure if it should be invincible or have a certain amount of shield. More challenging if it were not invincible.

What do you think?