Let's see here, now how do Revenants work in Doom... ok, let's see how well this translates.
Name: Santanant
Type: Dark/Ghost
Stats: Moderate health, high attack/special attack, low defense/special defense, high speed/evasion
Moves:
Homing Missile: (High damage, never misses)
Shadow Punch: (Standard move)
Missile Guard: (Creates an orbiting missile about itself, which does heavy damage to any pokemon that lands a melee attack in the next three rounds)
Homing present: (Fires a missile at target, which will inflict damage of a random type, cause a random status effect, or even heal the target. Yay randomness!)