Disowned Ancestor

The body for one black mana is pure defense: a 0/4 that trades into nothing but stonewalls early aggression indefinitely. Outlast is the patience tax that pays for the upside; each activation taps the creature at sorcery speed, so the turn you grow it is a turn it cannot block. The wall protects you only while you are not investing in it, and every counter buys long-term reach at the cost of a present-turn defender. The mechanic rewards a stalled board, where a creature that taps to outlast is not missing any combat anyway and a clock ticking one counter per turn quietly outpaces an attrition war. On its own the math crawls, which is why the keyword leaned on payoffs that cared about the counters rather than the bodies, cards that read the board for creatures with +1/+1 counters and turned a rack of slowly-fattening walls into a real threat. Read in isolation, this is a defensive one-drop that converts idle turns into a clock the long game eventually cannot ignore: it asks nothing of you until the ground has locked up, then makes standing still profitable.