Psychic Bolt

If you paid 2 life to cast this spell, Psychic Bolt
deals 2 damage divided by up to two targets.
Draw a card, then discard a card for each
creature killed by Psychic Bolt.
If you paid {r} to cast this spell, Psychic Bolt
deals 4 damage to target creature or plainswalker,
if that permanent would be destroyed this turn
exile it instead.