when i move from The Ball, triggers before Assault and Shield apllication?

Radiance rules aren't published yet. This uses the printed card and current rules only, and it isn't a ruling on the new mechanics.

Yes — the move trigger resolves first. When The Ball (made a unit gear by Orianna, Lady of Clockwork) moves, the move completes, Cleanup puts "When you play or move this, choose one" on the Chain, and a Showdown can't begin while a Chain exists (Rule 340 / FAQ #6117). So the trigger chain finishes before combat starts — that's also before the Attacker/Defender designations are established at the start of the Combat Showdown (Rule 466.2.c).

Assault and Shield are just passive +Might that switch on with those designations (Rules 807.1, 814.1), so they're active only after your trigger has already resolved, and there's no window to react to them at all since they never use the Chain (FAQ #11234). Practically: your "Deal 2 to enemy units here" happens before Combat Damage, and anything it kills is gone before designations/bonuses are set — and if The Ball itself leaves play during that Chain, it won't be part of the combat.

One wording check: The Ball's trigger is about The Ball itself being played or moved, not about other units moving away from the battlefield where it's deployed. Note also that if it moves to an empty battlefield there's no Combat at all, so no Attacker designation and no Assault/Shield to apply. This is my interpretation based on the move-trigger/Showdown sequencing and passive-keyword rules; no official FAQ exists for this specific interaction.