Fatespinner

Hand a player a punishing decision and let them pick the least bad outcome: that is the whole engine here. The opponent chooses which step or phase to skip, so they always keep the part they need most this turn. The genius of the design is that it taxes tempo rather than dictating outcomes. Strip an opponent of their draw step and they fall behind on cards; take their main phase and they cannot develop their board or cast their spells; cut combat and a board full of attackers sits idle. None of those is fatal, but every one of them costs a turn's worth of momentum, and the choice itself is the punishment because there is no clean answer. It is a denial effect dressed as a Rorschach test, asking the opponent to confess what they were planning before they get to do it. The fragile 1/2 body is the cost: it dies to almost anything, so the controller has to protect it the way you protect any soft-locking permanent, leaning on counters and bounce to keep the upkeep trigger firing turn after turn. Stack the effect with other phase-denial or tax pieces and the opponent runs out of acceptable sacrifices fast, which is where it stops being a nuisance and starts being a prison. A genuinely mean piece of design from an era when blue was still allowed to tell opponents which of their turns they were not allowed to have.