Energumen (Su)

Once per day at 2nd level, a demoniac can open his soul to a demonic spirit as a free action. This spirit possesses the demoniac for a number of rounds equal to his demoniac level, granting a +2 profane bonus to one ability score of the demoniac’s choice.

At 5th level, energumen grants a +4 profane bonus to one ability score, electricity resistance 10, and a +4 bonus on all saving throws against poison.

At 7th level, energumen grants a +6 profane bonus to one ability score and also immunity to electricity and poison. When the energumen ends, the demoniac becomes confused for a number of rounds equal to his demoniac level as the demonic spirit has its way with his mind. At the start of each round of confusion, the demoniac can make a DC 25 Will save to end the confusion effect immediately.

Energumen is a possession effect, and is negated by protection from evil or protection from chaos. A demoniac can prevent or end the confusion side effect by having one of these spells cast upon him when (or before) the energumen ends, but being affected by such a spell before the energumen has run its course also causes the benefits granted to end prematurely.