Thundurus T is baller with Agility; I'm going to agree with PK on that. If you are in need of a really effective electric-type wallbreaker (read: you want to use Volt Switch), Expert Belt is the set you wanna go with imo. Heracross as a B-Rank? I'm going to say no. It's just not relevant to the metagame really... It's not fast enough or bulky enough naturally to do much without Choice Scarf, and with Choice Scarf, it's just too predictable and has coverage somewhat subpar for OU. Not to mention it's basically 100% inferior to Terrakion. I'm not going to try for a Moxie Sweep with Megahorn or Stone-Fail's accuracy, and Close Combat is planty strong on Scarf Terrakion. Especially with Gliscor and both Landorus being so popular/effective, and Hippowdon coming in as the more popular sand setter instead of Tyranitar. The recent Foretress > Skarmory helps Heracross's case a bit, but Heracross still lacks what every effective Fighting type in the metagame has: Speed, precisely 108 Speed, or Priority. Thing is Heracross is not only out performed by A and S rank Pokemon (Keldeo, Breloom, Terrakion, Genosect sort-of); it's also outclassed by B class ones (Lucario, Scizor), and frankly, even Conkuldurr and Infernape (C tier) are much more effective Pokemon overall. For weird substitute sets or mid-speed/bulky fighting types, Toxicroak (and Breloom of course) are much more relevant. Since Heracross isn't relevant to any type of weather except beating sand (which Scarf Terrakion does WAY better, especially not getting hit by sand damage), and is inferior to other Fighting types in OU in bulk, speed, no priority, and even in base ATK, I'd say ~D or lower makes sense. Heracross does sound about as relevant to the metagame as Metagross. btw-- usage in UU means jack shit here.