The question arises because Spike Armor places an effect on Sandslash, which gets triggered by the opponent attacking on their next turn. It's not an effect of an attack, it's an effect of an effect of an attack It's also not an effect done to the Attacking Pokemon, at least not initially. Holon WP does not prevent the effect from going on Sandslash, but does it prevent the subsequent placement of damage counters when Sandslash is damaged? [EDIT: Took out the stuff w.r.t. Lucario LvX since it's not actually relevant] Addendum: Reference the ruling on Fluff vs. Dark Seed: Holon WP can't stop the creation of Sandslash's effect, since it resides on Sandslash. Based on the Fluff ruling, it shouldn't be able to prevent the damage counters either. Holon WP only keeps the effect from being created in the first place -- if it gets created, it must then resolve, and Holon WP can't do a thing about that.