The Battle of the Cousins is the longest ever battle,showing Ben fighting his cousin,DarkGwen.
Ben:Gwen,there is still good in you!I know it! DarkGwen:You must die,Ben!I will be Queen DarkGwen! Ben:Don't do it! DarkGwen:I'm done taking orders from you,Ben!You know that now!You will DIE!!!!!!!
Ben used the Omnitrix Master Control to weaken DarkGwen,but DarkGwen used her anodite powers to create a sword with a gold handle.
End of the battle
Ben defeated DarkGwen,but took her captive instead of killing her.Ben put energy cuffs on her wrists to stop her from using her dark anodite powers.When DarkGwen was defeated,she had scars on her face.