I would nominate Accelgor for C rank but oh well
Anyway, Chandelure should go up a rank, to C+. This guy is an excellent revenge killer, a wallbreaker and a spinblocker all in one, thanks to its massive special attack stat, its ghost typing and its Flash Fire ability. It can kill any Landorus, Thundurus and Aegislash with just a bit of prior damage, while also threatening Rotom-W, Quagsire and Azumarill with Energy Ball. Heatran is not safe either, as it risks eating a Hidden Power Ground to the face or being tricked a Choice item. Another great set is the SubSplit one, which takes a massive shit on stall and can kill at least two Pokemon if it sets up a sub safely. Mega Charizard Y may have Drought and even higher special attack, but it can't hold any item bar the mega stone and is quad-weak to Stealth Rock. Volcarona is also quad-weak to SR and weak to Brave Bird (HI TALONFLAME), meaning it can't use Choice items effectively. That's why I think Chandelure deserves C+.