Morel Mackernasey

{2}: Create a smoke clone
{4}: If a creature blocked Morel both go into an exile state. While in this state both can't use their abilities and can't be targeted by spells or abilities.
The other creature will get a smoke counter each
turn and once they have an amount equal to or above power and toughness combined that creature dies.
Morel returns to the battlefield when the creature
dies.