Mediumship

So, there is this character that has the power to connect spirits to the real world at will, making them visible and audible without the veil between Ghost™ and Human™ world being weak.

S/he was raised by a cult, where he was made to believe he was some sort of god who would connect both worlds, but he's in fact, just some powerful human.

Which kind of power could fit alongside talking to ghosts?