How does Slaking's "Lazy" Ability or any other form of Ability denial that only applies to Pokemon "in play" interact with Abilities like Giratina's "Distortion Door" Ability that puts a Pokemon card from the discard pile onto your bench?
Since Distortion Door happens when Giratina is not in play, you can use it to put Giratina onto the bench regardless of Lazy or other similar Abilities. You also get to put the damage counters onto your opponent's benched Pokemon too, because you must complete the action of Distortion Door prior to it being shutoff due to Lazy.
Distortion DoorLazy