This tier doesn't have much activity, but I would like to argue for Mega-Gyarados to rise. With access to Mold Breaker and Taunt, it is a very effective stall breaker. It can set up on Sableye-Mega, isn't walled by Quagsire, and resists Dark-type attacks to an extent. Aside from Fairy-types --- by which I mean the 2 (3 if DA's Sylveon counts) --- Mega-Gyara can break most members of stall.
Although, its daunting weaknesses such as its Fairy-type weakness, no realistic bulk due to lack of recovery options outside of rest (which effectively nulls its best role as a stall breaker), and low speed.
C- -> C+