Ninjago, Season 4: Tournament of Elements

Lloyd:
Father, I don't understand. You trained under Chen, yet you fought beside Wu in the wars. What happened to the truce?

Garmadon:
When Chen said "Never trust a snake," he was right. The Serpentine struck first. The alliance of the Elemental Masters fought back. But they had never seen the likes of an Anacondrai warrior. They were bigger, smarter, natural leaders on the battlefield. The Anacondrai were a proud tribe who fought with every ounce of venom. There was no greater warrior in the land. And with them in command, they proved to be too much for the alliance to handle. Chen stood to gain more if he sided with the snakes and wanted me to help him. Though the evil in my veins tempted me, I wouldn't fight a war for him. I would only fight to see Misako again. From then on, Chen and I went our separate ways so that I could join my brother in battle. We were the sons of the First Spinjitzu Master. And together, with the Elemental Alliance, we stood a fighting chance. But Chen's influence changed all that. He found a way to turn the alliance against each other. The battle was all but lost. But in our darkest hour, we found hope. And hope found a way to end the war. The Serpentine were divided and locked away in tombs. Chen and Clouse were exiled. And the Anacondrai generals were given the strictest sentence: banishment to the Cursed Realm so that they will never set foot in Ninjago again.

Lloyd:
Even after all this time, you never told Wu about your past with Chen?

Garmadon:
What would I have said? I would have lost your mother, as well as my brother, not to mention—

Lloyd:
Someone once told me you need to control your fear, and not let fear control you.

Garmadon:
Hm, you're right. Once we put all of this behind us, I'll make things right. But first, we need to find Nya. Come on.