this came up as a big thing against a certain wagon driver in some casual games.
Reversal: (Response) - R Reveal this card from your hand: After an opponent’s
attack has resolved, if a player with this card successfully blocked the attack, he
may immediately attempt to play this attack from his hand, proceeding as if he
played a regular attack. Once this attack has resolved, his opponent continues
with his Combat Phase. A player may only attempt to play one Reversal per
just confirming that if i have 2 cards in hand, block and then go for a reverse pommel smash as astrid, he can check a 5 and discard it by responding to the cost of reversal.