I'm going to second this nomination.Kyubes for A-
It's time for this monster to move up. Many people are already starting to realize how fucking good this monster is right now, and it's easy to see why. It demolishes balance. Practically nothing switches into the special attacker LO set bar a few things which are easily exploitable by a teammate. The BoltBeam + Earth Power coverage is more than enough to take a dump on all the Ferro - Bro - Gliscor balance teams going around, and even other defensive cores such as VenuTran, HippoTran, and Altaria + Steel-type fall to this monster. Its speed, while not that great, is actually in the perfect spot for a wallbreaker such as Kyubes. It has astronomical bulk, which is bolstered by its access and ability to reliably use Roost. Finally, it's able to attack from both sides of the spectrum without sacrificing power like many other mixed attackers. 170 / 120 offenses are nothing to scoff at, especially when one is fully invested while the other still takes advantage of a Life Orb. This leaves Kyubes with very few 'true' counters, which are honestly limited to bulky Mega Scizor, AV Conk (which is more of a check tbh), and Chansey should Kyubes lack Outrage. Other things that check it, such as Clef, Sylveon, and Keldeo. Are either bopped by a coverage move, or unable to switch in should 20% of their health be gone, which can be achieved through basic team support. I realize Kyubes has its flaws such as a poor matchup vs. offense (which can actually be remedied with a scarf set), and a poor defensive typing, but neither one is enough to prevent Kyubes from moving up, especially when 10/10 teams it faces have no counters for this thing. 'A' rank is a different story, however.
Also js but it's really funny when opponents send in their unevolved Metagross and expect a switch, only to get bopped by an Earth Power.
Regardless, move this monster up. Kyubes for A-
I've played a few matches with two Kyube sets (Scarf and LO), and this thing has demolished opponents in each of my matches. Despite having a poorer match-up vs offense, the threat of switching into a Scarfed set saved me momentum while my opponent tried to avoid bringing in something that would lose to it until I revealed the LO.
The prevalence of Balance at the moment means Kyu-B's LO set has a field day demolishing common defensive cores, and while his typing isn't great, it does offer a few decent resistances to switch in on Electric types, resisting their STABs and his bulk offsetting HP Ice, bulky waters that have to fear Fusion Bolt, and his bulk just helps against slower mons he might need to break like Hippowdon. His mixed attacking abilities regardless also just make him tricky to wall considering his decent coverage on both spectrums and Teravolt.