Mercer, Master of All

If you would lose unspent mana, that mana
becomes black instead.
Whenever a none token creature dies create a
none legendary shadow token which is a copy of
that creature create two if that creature was
legendary
Cloudkill: {t} Tap and sacrifice ten untapped
Shadow tokens you control: Each opponent loses
10 life and you gain 10 life.
Partner with Fluffy the Endless hunger