Byro, Plague Doctor

Protection from Undead (Wraiths, horrors, liches, skeletons, specters, spirits, vampires, and zombies are
all considered undead.)
If a creature you control were to get a +1/+1
counter, you may instead put a -1/-1 counter on another target creature.
{w/b}{w/b}, Exile a creature from your graveyard: Put a
+1/+1 counter on target creature you control.