Bloodchief Ascension starts as a one-mana enchantment that rewards repeated pressure on opponents' life totals. At each end step, it can gain a quest counter if an opponent lost at least two life that turn. Once it has three counters, cards entering an opponent's graveyard can make that player lose two life while you gain two, turning common game actions into a powerful drain engine.
Small attacks, damage spells, and effects that cause life loss can help establish the initial counters. Because the check happens at every end step, you can advance the enchantment on opponents' turns as well as your own. A deck with instant-speed damage or repeated life-drain effects has more opportunities to bring it online quickly.
Mindcrank forms a dangerous pairing once Ascension is active. Life loss makes an opponent mill cards, and those cards can trigger Ascension again, creating a repeating interaction while the necessary conditions remain in place. Even without that combo, opposing fetch lands, discarded cards, destroyed permanents, and milled cards can all provide triggers.
The setup is the important limitation. Ascension does little immediately unless it already has the required counters, so it is strongest in decks that can reliably deal early damage or drain life. Tokens entering a graveyard are not cards and do not trigger its second ability. Keep that distinction in mind when judging how much value an opposing token sacrifice deck will provide.
