This can be by preventing your opponent from attacking you, or by stopping them for activating certain effects: if your opponent cant do what they normally would, theyve been stalled
You can only use each effect of "Electric Jellyfish" once per turn
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You can obtain special Reward(s) and a large amount of Event Points by defeating him
Heads: Negate your card effects that target this card, and if you do, destroy them
Activate Bartolom del Presidio to sacrifice that fourth creature, thanks to Ygra, Eater of All, Experimental Confectioner triggers, and creates a fresh Rat token that you can again sacrifice with the vampire knight