In the Overview mention Poison Heal grants Gliscor not only immunity to status, but also an incredible 12.5% / turn recovery, the main reason why it's so hard to take down Gliscor without powerful blunt attacks.
The ban of Sand Veil affected its SubSD set, so you should specify which Substitute set you're referring to on your Overview.
Although Landorus-T and Garchomp offered new threats that Gliscor can check, the former provides competition for the defensive Ground slot, as it can check Terrakion and Garchomp just as effectively as Gliscor, thanks to Intimidate, while also packing major punch. You should note this in your Overview.
The first Substitute sets need re-ordering:
move 1: Substitute
move 2: Toxic
move 3: Protect / Taunt / Roost
move 4: Earthquake
As you can see I made Toxic a staple instead of an alternative, and slashed Taunt with Protect / Roost. Ice Fang is only worth an AC mention.