Undead Paladin Leeroy

Undying(When this creature dies, if it had no
+1/+1 counters on it, return it to the battlefield
with a +1/+1 counter on it.
Protection from white.
{b}{b}{b}: Regenerate target skeletons with
up too converted mana cost 4 or less.
{b}{b}: target opponent sacrifices an artifact or enchantment.