unhiding pheonix egg ablility button

I'm making the pheonix egg ability as a Hero spell, but its ability button won't show, even I place the button position correctly. Is there a way to unhide it??

Second Problem.. when the hero with pheonix skill dies, it is replaced by another hero. Example level of the hero is 10, after the phoenix skill, it becomes level 1.

That abilty only creates a new unit, it doesnt revive the old one. I suggest you use Rencarnation and change the model from the cross to the egg.