For the Hollow One mythic path from Mythic Paths of the Lost Spheres:
Soul of Conflict
You may pit creatures one against each other within you, drawing their attentions away from controling your vessel and locking them into a mental battle for dominance.
Prerequisites: Have experienced or are currently under the effect of a possession attack by a creature.
Benefit: As an immediate action, you make force any two entities attempting to control you via possession with the past round to roll opposed Will saves against each other as they become mired in the depths of your spiritual essence. Resolve the physical aspects of each attempted possession as normal (bodies merge or are left vacant etc.) as the creatures both begin to initiate a possessing effect. You then oppose with a Will save a DC equal to the result of the higher possessor. If you succeed both creatures control over your is negated and you may act as normal until conditions change control. If you fail, the possession effect of the dominant possessor resolves normally.
Note: This is NOT a mythic feat and can be taken by any character meeting its pre-requisites.