Hello! I just want to share some sprites... :)
Mega Ampharos (front sprite by capylus, I know you already have a front sprite so I don't expect you to accept this; back sprite by thedarkdragon11 and HeXeR):
Mega Sceptile (front sprite by The Cynical Poet, Kyuzeth, TrainerSplash and Versekr Dark; back sprite by Versekr Dark):
Mega Blaziken (front sprite by Remus Lupin; back sprite by Silver Death and Versekr Dark):
Mega Aggron (front sprite by capylus, wally-217 and Versekr Dark; back sprite by Versekr Dark):
Mega Metagross (front sprite by Versekr Dark; back sprite by HeXeR):
Mega Latias (front sprite by MyMarshlands and thedarkdragon11; back sprite by HeXeR):
Primal Kyogre (front and back sprite by Nickblorck):
Primal Groudon (front sprite by Nickblorck and thedarkdragon11; back sprite by Nickblorck):
Mega Garchomp (front sprite by Legitimate Username and thedarkdragon11; back sprite by Versekr Dark):
I hope these sprites help...