252+ SpA Choice Specs Raging Bolt Draco Meteor vs. 244 HP / 12 SpD Gliscor: 454-535 (128.9 - 151.9%) -- guaranteed OHKOI'd honestly reckon the powercreep brought on by the Indigo Disk is largely why Gliscor's okay in the tier. I believe there are a lot of things that are capable of downright pulverizing the bat and blasting it apart in one or two blows. Archaludon, Speedeoxys, Darkrai, Raging Bolt, Kyurem and even variants of Gouging Fire. Iron Boulder's Mighty Cleave helps a bit in breaking past its constant Protect spam too.
252 SpA Life Orb Darkrai Dark Pulse vs. 244 HP / 12 SpD Gliscor: 220-259 (62.5 - 73.5%) -- guaranteed 2HKO after Poison Heal
+2 252 Atk Quark Drive Iron Boulder Mighty Cleave vs. 244 HP / 252+ Def Gliscor: 235-277 (66.7 - 78.6%) -- guaranteed 2HKO after Poison Heal
Gliscor is no more with the power creep indeed.