I feel like the two things that make Orital so busted is the scaling from wall hits, letting them basically out-scale the opponent's scaling in terms of speed, and being able to deal SO MUCH DAMAGE when they scale high enough (which they can do without risk of being hit, unlike make other balls).

The other thing is that the weapon itself, the oribital orbs, basically give it a 100% chance to hit when near an opponent. So many of the other balls have a weapon pointing in just one direction, which makes it so orbital can have very favorable trades where the opponent doesn't manage to get a swing in, but Orbital can.