Paladin of Ragnarok

Defender
Paladin of Ragnarok has X power - where X is the number of half the Black lands you control.
When there's at least 1 creature with more than 6 converted mana, Paladin of Ragnarok can attack as
long as that creature attacks.
{x} {b}{b}- Destroy X target creature/s. You will gain
a life every 2 creatures destroyed. Then, exile this creature.