Shynn, Deep Wood Regent

Whenever a creature attacking you dies during
combat, create a blood token.
{b}, Sacrifice a Blood token: Target non swamp land
becomes a swamp in addition. The land's controller
then loses life equal to the number of swamps they
control.
{r}, Sacrifice a Blood token: Put a +1/+1 counter on
a target creature you control, then gain life equal to
its toughness.