After Clark returns from the dead, his powers don't come back with him. Cue angst, whump, Clark and Bruce desperately trying (and failing) to restore Clark's powers, and Clark struggling to cope with his new human body and its limitations. He doesn't want to give up crimefighting entirely, so he seeks help from Batman to learn how to adapt and fight without the luxuries of super strength, amongst other things. Is he still Superman, or a different alterego entirely? Up to you. My kingdom for bottom!Clark.
Bruce/Clark, Clark is permanently depowered