MegaMeganium
Dropping Bloom Dooms
Why would I encore a banded Azumarill? Ever heard of belly drum? Also, Shuckle is THE ONLY POKEMON with access to both rocks AND Sticky Web. Also, you have NO IDEA how many battles I've won because of Shuckle. And I thought of a new application; what if the opponent ALSO uses Sticky Web? They effectively cancel each other, because both sides now have -1 speed.252+ Atk Choice Band Huge Power Azumarill Waterfall vs. 252 HP / 4 Def Shuckle: 228-270 (93.4 - 110.6%) -- 56.3% chance to OHKO
Good luck getting the chance to Encore that. Also, it's Banded, why use Encore?
252+ Atk Life Orb Excadrill Iron Head vs. 252 HP / 4 Def Shuckle: 182-218 (74.5 - 89.3%) -- guaranteed 2HKO
Any prior damage and you won't get the chance to Power Split. And I'm pretty sure that's still a 2HKO if Power Split is used after the first hit.
It does beat Serperior, I'll give you that, but for dealing with TFlame and Mega Aerodactyl there are much better SR users out there. Sticky Web is not as necessary as you are making it out to be, given that Speed passing is very gimmicky and going from +5 Speed to +4 Speed really doesn't do much. Scarfers are also less common now and the most common Scarfer is immune to Sticky Web anyway. We also don't need Keldeo to sweep, given that it's main role is removing slower mons that can give Alakazam hell.
I really like the Clefable, however, I would use a spread of 252 HP/124 Def/132 SDef so that you can switch into Thundurus without being 2HKOed by Thunderbolt, especially since Thundurus gives our current members of our team hell. For the slot after this one I'd really like to get a Stealth Rock user, preferably one better than Shuckle. I'll probably throw in a suggestion of my own for that next round.