Chara, The Monster Within

Constellation- Whenever this or another
enchantment enters the battlefield, each opponent
may sacrifice a creature. If they don't, they lose 10
life and draw 10 cards. You take X damage, where
X is the number of excess cards beyond 7 drawn.
As long as your devotion to black is less than 7,
this isn't a creature.
Bestow: Sacrifice 10 creatures: Enchanted creature
gets +10/+10 and becomes goaded.