Here is a chess position that seems illegal (as in it can't be achieved) however it can be! How?

If you're referring to black having two dark-squared bishops, then obviously s/he has promoted a pawn to a bishop. I'm not going to work from scratch and figure out a path to that position though :P

Rxg7 Qxg7 Qxh5 mate

or

Rxg7 Kxg7 Qb7+ and ill let you work out the rest.

Re7+ first, Qb7+ to follow :)

yes that's was the only object of the puzzle:D

Guys! Read his post! He's not asking for a mate solution.

Umm, the objective is to mate, not to take his queen, plus queen goes Kf6 if Re7+

I know this isnt to solve the puzzle, but I wanted to.

You'll have to show me the mates after black's 2nd moves then   : /

Yeah but you answered it right off.  Even to me, who is terrible at these "legal or illegal" puzzles saw that one

Haha. Ok, fair point! :)

it is not illegal... a pawn converted to bishop....