Kira Yamato and Athrun Zala in “Unfinished Business”

Kira Yamato

I know what you're saying... I know what you're saying, but it doesn't matter. Because at this moment, Cagalli is crying her heart out. She's crying because all of this is exactly what she feared. Why won't you understand that? And now, are you telling me that this battle... these terrible sacrifices... they can't be helped!? That all of this is the fault of Orb and Cagalli? If you are saying that, then you are attacking the very thing that Cagalli is trying to save!

Athrun Zala

[Athrun is shocked by Kira's words] No, Kira... I...

Kira Yamato

Then I have no choice. I must defeat you! [Kira enters SEED mode]