Olivia, Mobilized for War

You decide whether to discard a card as the triggered ability of Olivia, Mobilized for War resolves. If you do, the rest of the ability’s effects happen before any player may take actions.

If the entering creature leaves the battlefield before the triggered ability of Olivia, Mobilized for War resolves, you may still discard a card. The rest of the ability has no effect.

If you discard a card, the creature only gains haste until end of turn, but the +1/+1 counter and Vampire subtype remain indefinitely.