I just recently did this fight! I was determined not to have to go back and switch out Pokemon for it. Luckily I had a focus sash, so Arbok held that to get Glare off. That at least made it so I'd be quicker than Arceus. Next turn Arbok used Acid Spray to lower the special defense harshly. Then I put out Meowstic to use light screen while holding the item that extends the number of rounds it's up for (I'm blanking on the name!) and Misty Terrain to change the field. After that it was just a matter of Meowstic and Arcanine whittling Arceus down with special attacks, with the rest of my team just fodder for me to revive and heal the main two. I lucked out at the end with Arcanine as my last Pokemon up. Arceus was too paralyzed to move a couple rounds when it should have killed me, but I was able to end it thank goodness.