Taraziel, Paincaster

Whenever an instant or sorcery spell you control
deals damage to an opponent, exile a card from
the top of your library for each opponent dealt
damage this way.
During each turn, if an opponent has lost life, you
may play cards exiled with Taraziel, Paincaster
If an opponent would be dealt damage by an
instantor sorcery, if that spell was cast from exile
it deals double that damage instead