So me and my friend are playing a game of phyrexians vs eldrazi, you know invaders vs invaders, and he brings out spellskite, next turn (I have ulamog out) I play emrakrul, as attack with ulamog, he says in response he uses spellskite to take ulamogs anhialator, and emrakrul a anhialator and both teir indestructible and flying, can that be done?