Whenever you put one or more counters on a creature, until end of turn, that creature can't be blocked by creatures your opponents control.
Steal — , : Move a counter from target creature an opponent controls onto target creature you control. Activate only as a sorcery.
Rikku is a mono-blue +1/+1 counters deck that turns counter generation into unblockable damage—any time you add counters to a creature, it can't be blocked that turn, letting you swing for commander damage or chip the table down. You build up proliferate and counter-doubling engines, then convert a single beater into an evasive threat, while Rikku's Steal ability lets you strip counters off opponents' creatures to neuter their bombs and pad your own.
Reliable evasion: any counter placement makes a creature unblockable, enabling consistent voltron/commander-damage kills
Mono-blue gives best-in-format card draw, counterspells, and protection to defend your threat
Steal disrupts opponents' planeswalkers, sagas, and counter-based bombs while growing your board
Synergizes with the deep +1/+1 counter and proliferate support pool
Relies on a single threat carrying counters—vulnerable to spot removal and board wipes
Mono-blue offers little instant-speed removal or recursion if the engine is disrupted
Steal is sorcery-speed and one counter at a time, so it's slow against go-wide boards
Can be low-impact in the early turns before the counter engine comes online
Repeatable counter source that triggers Rikku each turn while pumping your team.
Add counter-doubling stax-lite pieces (Hardened Scales, Branching Evolution, Conclave Mentor effects with proper colors aside) and proliferate density to make Rikku trigger every turn, plus protection like Swiftfoot Boots, Heroic Intervention substitutes, and counterspells to shield your threat. Lean on cheap evasive bodies that scale—Walking Ballista and Hangarback Walker double as removal and counter banks. Tighten the manabase with fast rocks (Sol Ring, Mana Vault) and a strong card-draw suite so you reliably present a lethal unblockable creature by mid-game.
Legendary Creature — Human Artificer
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: Move a counter from target creature an opponent controls onto target creature you control. Activate only as a sorcery.