Vraska, Betrayal's Sting

The ultimate expression of what proliferate was built to do: her -9 does not slowly stack poison over several turns, it reads the counter delta and closes the gap to nine in one activation, bringing a player to the brink of a poison loss in a single loyalty payment. That makes her the payoff at the top of a toxic-and-proliferate curve rather than a piece of it, and the plus-adjacent 0 ability feeds that plan by proliferating every turn while it refills your hand, so poison you have already dealt keeps climbing even on turns you spend developing. The Compleated keyword is the part worth studying: paying the hybrid pip with two life lets you land her a turn early, but she arrives with two fewer loyalty, so the discount is charged against the exact resource her ultimate needs and against the buffer that keeps her alive. That tension is the whole design. Her -2 is the pragmatic floor, a hard answer that strips a target creature down to a Treasure artifact, shedding all card types and abilities so it dodges the usual "can't be destroyed" and reanimation escape hatches. Note that control does not change: point it at an opponent's threat and you are handing them a mana rock, not taking one, so the -2 is neutralization by demotion rather than theft. She is a rare planeswalker whose emblem-tier finish is not incremental value but a discrete, math-driven setup toward a poison loss, and every other line on the card exists to buy the time to reach it.