Aster Phoenix is a Pro Duelist and an ally of Jaden Yuki who serves as a protagonist in Super Smash Bros. Crossover. Aster first appears when Sasuke Uchiha (who is disguised to blend in) challenges him to a duel. Aster accepts, unaware of who his opponent is, and believes he will win since Sasuke has never dueled at the Duel Dome. However, after Sasuke summons Hamon, Lord of Striking Thunder and Red-Eyes Darkness Dragon, Aster demands Sasuke reveal his identity, which Sasuke does, and Aster is horrified to learn his opponent is a wanted criminal. Aster tries to defend himself with his Destiny Heroes, but is defeated in one strike and seriously injured in the process. Aster later recovers and travels with Jaden to the Land of Lightning, hoping to get payback against Sasuke.
Aster's appearance is based off his appearance in Yu-Gi-Oh! GX.
Aster shows signs of arrogance, since he thinks beating Sasuke will be easy as he was unaware of Sasuke's identity because Sasuke was in disguise at the time. However, Aster became cringed in fear after learning Sasuke's identity. Aster also holds a grudge against those who wrong him.