It is of my opinion that Revenants are little more than a nuisance.
the problems in my opinion are
Essence gained is usually very low unless the dead person you aren= sucking is still in their corpse
I think critical players can be leeched, but everytime I've tried I get a message about their life force being too strong. so possibly making it able to leech anyone unconscious except the SSD.
Reduce the cost of powers, due to essence being so limited, spending essence to talk when the cost of talking was one whole leeching.
Lightning is a trap, it won't kill anyone, and it costs points, useless, either remove the cost, increase the wait timer, or increase the damage exponentially
they need more things to do as well
now all of this would be OP, and is just my opinion, please share your own and collaborate