Maybe something like this:

*they are out fighting*

Shinn: Argh it's Athrun!
Luna: OMG... Athrun is alive?
Athrun: YES! AND SO IS MEYRIN!
Luna: Really?
Athrun: Yes, come and join her!
Shinn: LIES!

*Shinn and Athrun fights*

Luna: Stop this fighting, I will now defect and be reunited with my sister!
Rey: TRAITOR! *shoots Luna down*
Shinn: REY!!!!!!!!!!!!!!!!!!!!!!111
Rey: She was a traitor. There was no choice.
Shinn: *SEED MODE*

etc