Ishimaru

Defender taps Ishimaru to take an attack. Once per turn, as a Response, you may discard 1 to untap it. In an attack, responses come before Defender, so after it takes the first attack, discard in the next attack’s response window and redirect that one too: two blocks in a turn.

Carapace 1 on 4 health means no single attack of 4 or less kills it, and a 2-attack entity deals only 1. Entity damage clears at the end of the turn, so your opponent has to finish it in one turn: two 3-attack hits or one hit of 5 or more.

With 0 attack it never damages what it blocks; it buys time. That suits decks that win late, like Cat’s Bobu list, which also plays Treetop Scout: Ishimaru is an Obsidian, so the Scout can find it from your top 5. The untap costs a card, so save it for the turn the second block matters.

Infiltrate, like Scarlett’s, skips Defender entirely. Ember Marksman’s 4 damage to a Defender leaves it at 1 health after Carapace, while Fire Orb’s 5 kills it. At cost 5 it is out of reach of Lotus of the Mizuryuu and Shao’s Perseverance.

Rooted doesn’t stop Defender, so it still blocks after Lord of the Woods, Kasumigami or Entangled Fate. But a Rooted Ishimaru is a target for Silence, whose destroy ignores Carapace.

From the full set, Suna the Wayfarer makes it cost 4, and its Defender takes 1 off Craggy Beanz.