I'm backing up Victini for S-Rank. The thing is just obscenely powerful. Both of its offensive stats are solid, but as Magcargo 2 said, it has absurd power in both viable STABs making it really hard to take a hit from. It can run both physical and special sets so it is rather hard to directly counter. As stated, Victini has quite the great offensive movepool as well, so it has a lot of coverage options; good luck walling it. Being SR weak doesn't necessarily matter, Blastoise does a great job at spinning so SR is rather easy to keep off the field. Undeniably a top threat and something to be prepared for, an easy S-Rank.
Accelgor and Scolipede deserve to be in the C-Rank. Both are great at spiking thanks to their admirable speed tiers, and they can do the job pretty well. They receive stiff competition from Froslass, however, their solid offensive prowess makes them worth the use if that is needed. The two are both great offensive Pokemon as well, and Scolipede can run an SD set while Accelgor an All-Out Attacker, and the two have solid coverage with their power to put some dents into teams, despite some competition. Overall, I think they're both decent assets to offensive teams, and they do have competition in their roles, but they deserve to be at least C-Rank.
Does Uxie deserve to be on the list? I haven't used it a lot but I'm sure it's viable to some degree.
Accelgor and Scolipede deserve to be in the C-Rank. Both are great at spiking thanks to their admirable speed tiers, and they can do the job pretty well. They receive stiff competition from Froslass, however, their solid offensive prowess makes them worth the use if that is needed. The two are both great offensive Pokemon as well, and Scolipede can run an SD set while Accelgor an All-Out Attacker, and the two have solid coverage with their power to put some dents into teams, despite some competition. Overall, I think they're both decent assets to offensive teams, and they do have competition in their roles, but they deserve to be at least C-Rank.
Does Uxie deserve to be on the list? I haven't used it a lot but I'm sure it's viable to some degree.