Review Detail of Supper_mega in Deity of Destruction

I'll try but considering Reinhard's 'Love', it might be hard.

So many persons he love like true dragon sister , primodial demon like misari , rain and testorossa

Your missing the point. Reinhard's love is basically destruction. In other words, if he dares to love someone too much then his urge to destroy them will also intensified. That is why he cannot purely love a being

Even if you do romance in the future I hope this doesn't turn out to be a harem!

He doesn't have to be a perfect copy of the original Reinhard though since sounds like he was originally a regular guy from earth. Maybe after living a few thousand or million years he learns to have more balance to his love and there are some people he can love more than the destruction his love usually takes the form of. I'm imagining a mega yandere.

Nah, if that were to happen then he should just stop being Reinhard and start acting like Mercurius. Reinhard's throne is literally unchanging, he never wishes for nothing to change but still... I guess I can probably do that.

But in that case why not just make Reinhard himself reincarnate in Tensura if you wanted it to just be the exact version. What was the point of having a normal man reincarnate in the body of Reinhard with his powers I thought your whole plan was to eventually have there personalities mix and create a new Reinhard even if the original personality of Reinhard would probably always be dominate.