Well it is Giratina we're talking about here so such actions are to be expected from such a monster haha.
Didn't think about that there tbh but yeah that does sound like a good idea for Roserade to have Toxic Spikes and maybe Leaf Storm too for an unexpected punch haha. Milotic would be passable with Surf/Hydro Pump, Ice Beam, Recover, and either Toxic or Mirror Coat for its moveset. Not sure on what to make of Spiritomb's moveset atm though.
Didn't notice the weaknesses that Houndoom and Lucario shared either sadly, I would suggest replacing Lucario with Houndoom in that case but despite my minor dislike for Lucario overall I can't deny how effective it is in battle lol. Especially a set along the lines of Swords Dance, Close Combat, Extremespeed, and either Earthquake, Stone Edge, Crunch, or Ice Punch as its last move lol.