It's a death battle, logic gets thrown out of the window. :p

But the entire point of the Death Battle is to apply logic to decide who would win, not to let character popularity or fan interpretation win out...
Death Battle is all about logic.

About the skills of each character completely.

About why or how the characters would end up fighting each other, not so much.
So two characters with the Nightmare Force isn't probably a concern for a death battle.

Also the fact celestia would be called solar flar as well is wrong due to I stated all ready that a male pony as the name solar flar

Fair enough.

Just call her Nightmare Celestia.

Or nightmare sun

That doesn't have the same connotations and naming conventions.
While Luna's name did change to Nightmare Moon, "Luna" still means "Moon."
Meanwhile, Rarity's name stayed the same as Nightmare Rarity.

With that in mind, adding that "Celestia" doesn't mean "Sun", it's likely that her name would be "Nightmare Celestia."

I'll call her Bob.
What!? it's simple enough to remember.

I got it nightmare heaven due to celestia is also meaning celestial what means heaven

That's kinda contradictory.
But sounds nice.