So I'm looking at the top 50 stats and the following Pokemon aren't ranked yet:
Mega Heracross
Mega Scizor
Scizor
Conkeldurr
Thundurus-T
Cloyster
According to the usage stats, Mega Heracross was mostly used as a wallbreaker with the ability to ignore Sturdy, Sashes, and Substitute, Mega Scizor was either a Swords Dance sweeper or a bulky pivot with U-turn and Roost, regular Scizor often had a Choice Band for powerful U-turns/Bullet Punches and sometimes had Lum Berry for SD sets, Conkeldurr was usually AV and had priority, semi-recovery with Drain Punch, and isn't too concerned about status due to Guts, Thundurus-T could be either a Nasty Plot sweeper or a Volt Switch user with Scarf/AV, and Cloyster was usually a Shell Smash sweeper. I'd support all of these to be ranked, but I'd like some discussion since I haven't used them.