Using Spirit Thief is not very complicated, the Player must simply hit the enemy and their Chi will regenerate. You can also upgrade this in speed, duration and even its counterpart, Chi Strike. It is well worth remembering, especially when fighting golems, that this is NOT a support style, and so is not affected by support immunities save for demon opponents. The Chi Strike aspect will damage any opponent in the game just fine, still draining a tiny amount more Chi than each strike uses up. Note that a rare few opponents are immune to the chi-drain effect, but not to the damage inflicted in Chi Strike mode.