Radiating Insanity

{b}{b}{b}Select a creature.
At beginning of upkeep toss a coin.
If it lands heads, the creature is sacrificed
inflicting damage equal to it's force, to be spread amongst as many targets as you wish.
If a creature or planeswalker was to die from receiving damage dealt this way, exile it instead.
Every time target creature dies, select a new creature, if no creatures are available pay 10 life
or exile this enchantment and any copies of it.