Doom Slayer

Whenever a creature an opponent controls dies,
put a +1/+1 counter on Doom Slayer.
{1} plus {1} for each time you ativated this ability
this turn: Doom Slayer fights target creature.
{0}, unattach all Weapons attached to Doom
Slayer: Attach target Weapon you control to
Doom Slayer. Activate this ability only once
each turn.