To start creating an Angel Chaos Chao, you'll need to start with a normal Chaos Chao. You can obtain one of these by hatching a Chaos Egg in the Chao Garden. To hatch an egg, simply place it in one of the Chao Gardens and care for it until it hatches.
Step 2: Increase its Goodness stat
To make a Chaos Chao an Angel Chaos Chao, you'll need to increase its Goodness stat. This is done by doing good actions in the Chao Garden such as helping other Chaos Chao, planting flowers, and playing games with it.
Step 3: Defeat enemies in the Chao Races
Defeating enemies in the Chao Races is a great way to increase their goodness stat. Try to aim to win the races or at least finish 2nd or 3rd.
Step 4: Repeat Steps 2 and 3 until the Chao becomes Angel Type
Keep increasing its goodness stat by doing good actions and winning races until its appearance changes and transforms into an Angel Chaos Chao.