So if I attacked with Combat Celebrant and Medomai the Ageless and I exerted Combat Celebrant, Medomai would attack twice. Does this stack and give me two extra turns if I hit the opponent with Medomai both times, or does it only give me one extra turn no matter what? Because if I get two extra turns, I can untap the exerted Combat Celebrant on the second extra turn and exert him on that turn, making another extra combat phase. So does this duo result in five combat phases in three turns? Or just three combat phases in two turns?
If Medomai deals combat damage during each of the two combat phases of the turn, then you get two extra turns after this one. Medomai cannot attack during those, but you get to untap the Celebrant in the second extra turn to attack with and exert for another combat phase during that exra turn. Net result: 5 combat phases during 3 consequtive turns, all yours.
Extra turns and phases are always inserted into the turn structure right after the specified the specified point when they are created, other already existing extra phases/turns don't matter for this. So
Your turn ([...] combat phase [...]) -> your opponent's turn
becomes
Your turn ([...] combat phase -> exra combat phase [...]) -> your opponent's turn
becomes
Your turn ([...] combat phase -> exra combat phase [...]) -> your first extra turn -> your opponent's turn
becomes
Your turn ([...] combat phase exra combat phase [...]) -> your second extra turn -> your first extra turn ->[...]) -> your opponent's turn
becomes
Your turn ([...] combat phase exra combat phase [...]) -> your second extra turn -> your first extra turn ([...] combat phase -> exra combat phase [...]) -> your opponent's turn
Sorry for the dead card name.
Extra turns and phases are always inserted into the turn structure right after the specified the specified point when they are created, other already existing extra phases/turns don't matter for this. So
Your turn ([...] combat phase [...]) -> your opponent's turn
becomes
Your turn ([...] combat phase -> exra combat phase [...]) -> your opponent's turn
becomes
Your turn ([...] combat phase -> exra combat phase [...]) -> your first extra turn -> your opponent's turn
becomes
Your turn ([...] combat phase exra combat phase [...]) -> your second extra turn -> your first extra turn ->[...]) -> your opponent's turn
becomes
Your turn ([...] combat phase exra combat phase [...]) -> your second extra turn -> your first extra turn ([...] combat phase -> exra combat phase [...]) -> your opponent's turn
Former Rules Advisor
"Everything's better with pirates." - Lodge
(The Gamers: Dorkness Rising)
"Any sufficiently analyzed magic is indistinguishable from science."
(Girl Genius - Fairy Tale Theater Break - Cinderella, end of volume 8)