Lucent, Dark World Netherlord

Madness {2}{b} (If you discard this card, discard
it into exile. When you do, cast it for its madness cost
or put it into your graveyard.)
When a spell or ability an opponent controls
causes you to discard Lucent, you may search
your library for a Demon creature card, put that
card onto the battlefield under target player's
control, then shuffle.