On your turn this helps you play through various hand traps, namely Nibiru
It is nice to have an ability that always does something so as to force a discard
Also, since there are Fusion monsters that only use high-level Gladiator Beasts, it's nice to see the heavy hitters getting some action (a shallow observation)
Dusknoir DP could be used to Dark Palm away any Pokmon your opponent is attaching Energy to
BeelStarmon ACE becomes an easy target for your opponents removal effects, especially with the overflow penalty, but once you drop down this gorgeous alternate art of BeelStarmon, you will be able to close out games way quicker
I recall reading that even ZeXal had a nice villain backstory and redemption factor, adding more value to the characters as fans can emphatize with them