When he bought the "Egg of Hope", I thought he would want/wish for a flying familiar like a dragon (and should match his high mana capacity), just for [travel] convenience. Then last few pages introduces a dragon-woman who uses mana to change a [limited] body part. Maybe there is a possibility for a new harem member/familiar with a bigger transformation ability - and could require lots of mana, which MC can provide (a certain liquid).