Dragon King of the South, Ao Qin Rex (南のドラゴンキング, 青クインのレックス; Minami no Doragonkingu, Ao Kuin no Rekkusu) is one of the fabled Dragon Kings and the fastest among all the dragons.
- Telekinesis: Rex has unique telekinetic abilities, surpassing even Ryūjin's.
- Teleport: Rex can teleport himself, other people and even entire towns with ease.
- Random Teleport: sends the opponent through an alternative dimension to a random place of the universe.
- Fire Breath: common to most dragons, produces fire.
- Supernova: creates a gigantic star which explodes into a massive fireball. It is the third most destructive of the Fire Breath moves.
- Black Hole: using his right eye, Rex creates a black hole which spaghettifies the opponent and a large part of the surrounding area.
- Heavy Flap: common to most dragon kings, flaps one's own wings to produce a heavy wind blast.