The rivalry with Jaden is what improved both of them. I dare say if not for Aster, Jaden would not have owned the Neo-spacians in terms of "defeat motivating improvement." Meeting people and creating relationships are essential to character development. So with that said, his destiny heroes needs no introduction.
As mentioned earlier, it's no wonder Yu-Gi-Oh wants to bring back Aster to duel with Yuya in YGO - Arc V! Being a commander of Duel Academy forces, he will debut in episode 104.