Serissa, The Forgiver

Whenever a Demon creature you control dies, you may create a Sin token attached to target creature (They're enchantments with "Enchanted creature has defender." and "Prevent all combat damage that would be dealt by enchanted creature.")
At the beginning of each end step, each opponent loses life equal to the number of Sins on the battlefield.

Serissa, The Forgiver can't be blocked by creatures with Sins attached to them.

{b/r}: Sacrifice a Sin token, draw a card.