For any future problems with....

[Jayson"Phonics"]

Cena's abilty, all the way down under glossary and timing break down

7a Effects you control (other than this card's text) that trigger on a Successfully Played card take place. In the event of more than one effect, you choose which order they occur.
7b Effects your opponent controls that trigger on a Successfully Played card take place. Opponent chooses the order. (This is where cards such as Over Sell Maneuver and Sustained Damage are played.)

This is for the constant arguing we get when I play Cena and I insist that Cena's ability happens before Sustain Damage can be played