How do you create chaos choa in sonic adventure 2 battle

To make a Chaos Chao you have to reincarnate your Chao at least twice. After that, give it 1 of each out of all 21 animals (Note: Do not give them Chaos Drives!). Yes, you can feed your Chao too.

If you want it to be an Angel Chaos Chao, raise it with any Hero character: Sonic, Tails, or Knuckles.

If you want it to be a Devil Chaos Chao, raise it with any Dark character: Shadow, Eggman, or Rouge.

If you want it to be a Light Chao, raise it with a mixture between the Hero and Dark characters and keep it Neutral.

When it evolves, it should be a Chaos Chao.

Hope that helped! :]