Kenja no Deshi wo Nanoru Kenja

Its gender bender isekai. What else 

both have a funny and OP MC both MC are trapped in a VRMMORPG-game both are in a fantasy/historical setting 

Wise and old master reborn as a cute white haired girl in a magical fantasy world 

both have male mc that awake up as female game characters they played both have to hide their character identities as one a demon lord and the other one of he seven sages of a kingdom but use a make up kit to turn his Gandalf like character in a cute girl an that the form he woke up in the isekai game world both are trying to use their game knowledge in their new world that like the game they played but not