All of the Xenoblade characters are rightfully in the conversation at their peaks but they only really maintain said peaks for a scene or two at most so I'm not sure how much it counts.
The god-killing trio of Sora, Bayonetta and Joker are my immediate thoughts, though Joker also falls into the camp of only holding his true peak for one key moment. Sora and Bayonetta are always broken and they're both
really
broken.
Let the voice of love take you higher,
With this gathering power, go beyond even time!