Kurapika

Kurapika is Kurta, a small forest people whose irises burn red under strong emotion and whose eyes are graded among the most beautiful objects in the world, which is why collectors pay for them. The Phantom Troupe killed the clan and harvested the corpses. Kurapika survived by being away at the time, and has organised every day since around recovering the stolen eyes and killing the people who took them.

The revenge has a price written into the power. His Nen chains work at full strength only against the Troupe, and one of them, Judgement Chain, will stop his heart if he breaks that condition. In Nen terms a restriction that severe buys enormous force, and Kurapika chose it deliberately. Scarlet eyes also push him into Specialist, a category he has no business reaching, and using it burns an hour of his lifespan for every second it is on.

The day job is the interesting contrast. He works as a bodyguard for a Mafia family so he can move in the world where stolen eyes are traded, and he is calm, courteous and organised right up until anyone mentions the spider. Togashi uses him to ask what a person spends to get even, and the answer keeps going up.