Cartouche of Ambition

The black entry in its Aura cycle is the one that doubles as removal, and the order of operations is the whole game with it. Because it enchants a creature you control, you have to commit the buff first: target your own creature, let the Aura resolve, and only then does the enters-the-battlefield trigger let you drop a -1/-1 counter on something. That sequencing matters, because if your creature is removed in response to the Aura, the spell fizzles and the counter never lands. Survive that window and the payoff is a clean two-for-one: shrink or kill an opposing blocker on entry, then leave behind a lifelinking threat that turns each swing into life back. The targeting is the wrinkle worth noting. The counter reads "target creature," not "target creature an opponent controls," so it can land on one of your own to feed a counters-matter payoff or to soften a creature you intend to sacrifice on your own timing. The -1/-1 counter also has a permanence most Aura tempo lacks: it is a stat reduction that stays, not a one-turn pump. The card-disadvantage tax that haunts every Aura still applies if the buffed creature dies, but the removal half has already happened by then, which is what keeps the math from punishing you the way a pure buff Aura would.