Ok so ive seen alot of people complain about beating arceus. I didnt have a problem with this fight at all so im kind of confused. I lost the first time not knowing he had full heals but here is the strategy that ended up winning it for me. I hope this helps
Step 1. Magnezone with sturdy pralyze till full heals our gone. then do a little damage with an electro ball. 2. switch in to garados aquatail twice. (judgement didnt 1hko) 3. swited into starter (typlosion) used flamethrower twice another no 1 hit ko. and then finished it off with lucario. i didnt even haft to use scrafty. and didnt need a quick claw or anything like that. i dont think i got crits. so moral of the story. paralysis op. hope this helps