If you reveal enemy hand with Scuttle, how long do they keep hand revealed?
To answer your question, when you reveal an opponent's hand via the Deathknell effect of Scuttle Crab, you reveal it only for as long as it takes for all players present to clearly read and understand the information.
According to Rule 424.3 and the RiftJudge FAQ #9700, revealing is a temporary state. Once every player has had a reasonable opportunity to understand the revealed information, the reveal action is complete. It is a one-time action triggered by the resolution of the Deathknell ability and does not require the opponent to keep their hand revealed for the remainder of the turn.
For the sequence of this interaction:
- Trigger: When Scuttle Crab dies and is sent to the trash, its Deathknell ability triggers and is placed on the chain.
- Resolution: When the Deathknell effect resolves, the chosen opponent must reveal their hand.
- Duration: You present the cards to all players at the table. Once the information is understood, the reveal ends.