I know of Sekiro and Khazan so far - Sekiro via its reflections and Inner variants, and Khazan via just repeating the boss fight where you fought them initially. I quite like both and think it’s cool to re-experience the fights if you feel like it. Which other soulslikes do that?
Lords of the Fallen allows you to repeat boss fights at any time from the vestige menu.
Do you get any rewards for doing so or just for the fun of it?
I’m not actually sure since I haven’t even used the feature.