Dalton, Disgraced Agent

Dalton, Disgraced Agent can't be blocked.
When Dalton, Disgraced Agent attacks you may discard a card, if a land card is discarded Dalton, Disgraced Agent gets +3/+3 until end of turn, if
a non-land card is discarded each opponent must discards a card that shares a card type with the discarded card, if a player cannot that player loses
3 life instead.