Klaus, the Death Bringer

{b} Regenerate Klaus, the Death Bringer.
{2}{u}{u} Klaus, the Death Bringer gets +6/+0
until the end of turn.
Whenever a creature dealt damage by Klaus, the
Death Bringer this turn dies, you may create X
colorless Mana Gem artifact token with
"{t}, Sacrifice this artifact: Add one mana of any
color.", where X is that creature
converted mana cost.