I feel like this team's trending toward a Spikes-less Explosion team intended to set up a particular late-game sweeper. I felt that way ever since Muk got the nod, and Egg being added to the mix makes it even more certain that that's the best route to go. The main problem, however, is that the typical late-game sweeper is Vap, but Vap wants a way to deal with Raikou, and the typical Raikou-remover, Gengar, is harder to fit on a team with a mutually Ground-weak Exploder like Muk that isn't also the team's main Phazer/Lax counter.
Another candidate is Curse Heracross: his downside is that he requires even more setup to get to work, but on the upside, he doesn't need Raikou out of the way. We might even be able to get away without Pursuit support; Missy gets Poisoned by Muk, and Gengar is 5HKOed by Fire Blast (or potentially burned by Flamethrower) while failing to do the same in return with Thunderbolt (and struggling to hit all the Thunders needed for the job).
One idea I've also had for teams of this sort is to kill two birds with one stone and make Rock Slide Steelix the endgame sweeper. His downside is that it only takes on Fire Blast from Lax to prevent a sweep from happening, but on the upside, there's a lot of Monolax out there, and all of his other counters are very much targetable by Explosion, not to mention that, as I already said, he kills two birds with one stone by being the main Snorlax counter in addition to being the sweeper.
In the spirit of CCATs being aimed toward using exotic Pokemon, and this CCAT's aim in particular to use a mon that's widely regarded as on the cusp of OU-level but difficult to make work, I'll suggest Heracross:
Heracross @ Leftovers
-Megahorn
-Curse/Seismic Toss
-Rest
-Sleep Talk
SToss is a slash in case we wimp out. Curse Hera is basically worthless until an endgame where all its counters are dead, and to ensure this happens against stuff like Skarm, we're shoehorned into running a pretty niche Lax set. So it's understandable we might want to take a middle-of-the-road approach and allow Hera a chance at doing something worthwhile in the middle game, especially as its typing is alluring in terms of checking Grounds. However, I find that it's not really as good as you'd hope it'd be at doing midgame Ground-checking, so I figure its best bet (apart from gimmicky EndRev sets) is to hold out for a favorable endgame.