Blood Donor feature on Asplode
 

Can the blood donor ability on Asplode be played as an interrupt? For example. You cast Asplode. The thief plays a nope, and then you pay the two blood.

Re: Blood Donor feature on Asplode
 

From the Glossary in Rules of Play.

Give Blood X
A keyword ability. When a player pays for this card, they may, as an optional additional payment, take X damage to also activate the Give Blood ability shown on the card.

You would have declare that you providing the additional payment (and getting the additional ability) when you play the card, so before the response is declared.