I got really lucky in this fight. He never created a single copy of himself, but the idea would've remained the same, I just got to beat him faster. Zodiac is key to being able to do any damage in this fight, as well as Kevin having a Super Gladiator Belt for the CP. Swingwichs are required and you have to stuff Kevin full of them to make sure the party stays alive. Joshua should have a Super Gladiator Headband and spam Dual Strike as soon as Zodiac is up, only healing/items if absolutely necessary. The Draigon can be hit with defense down so make sure to have Enfeeble as well on someone. Once he's gone, it's just like Cassius. He'll kill you almost instantly if you let him so be extremely careful. I never got any clones, but if he does make sure to get rid of them as fast as possible.
Cheers :)