Dark gift for a paladin
One of my players (human paladin) got smothered by Lorghoth the Decayer at Durst Manor, super dead. I took him aside and roll played the Dark Powers, explained how his soul was forfeit and offered him “a gift”. No questions, no hesitation, he accepted the gift. Other than bringing him back to life, I haven’t shown any manifestations of the gift yet.
Question: how should this affect his oath, and what benefits/drawbacks from the gift would be most appropriate for a paladin?