Hello! Cooper will remain stuck at aged seventeen and immortal, unless there is anything catastrophic he physically could not recover from without needing to reset, things like decapitation, bisection etc. In terms of his 'reset' healing ability, this would be nerfed and he would only have the healing of a mundane human. So while he could be seriously wounded, such as being stabbed or shot, he would heal but only at the rate of typical humans.

For his emotion absorption powers, this power would be nerfed. However, as this is something that's keeping him alive, this could be something that the Aurora 'freezes' meaning he will no longer need to do this in game to keep him playable without his powers.

Hope this helps!