I am going to assume that Arcade cannot target objects that are being held? Brain farting right now and having trouble coming up with any rules one way or the other.

From the LoSH rule book (page 34):

An object is considered hindering terrain unless a character holds it. A held
object is not considered terrain, and it can’t be targeted, destroyed, or taken away from the holding character.

A couple game effects (like the Disintegrate feat and Molecule Man's SP) allow you to specifically target held objects, but that is because they specifically say so in their description. Arcarde's SPs do not say so

Thanks! Didn't have the rulebook on hand.