Gliscor @ Leftovers
Ability: Sand Veil
EVs: 192 HP / 96 Atk / 220 Speed
Jolly Nature (+ Speed / - SpA)
- Earthquake
- Roost
- Stealth Rock
- Taunt / U-turn
This is much better, the EV spread allows you to always 2HKO max HP / 12 Def Metagross with Earthquake, while outspeeding Jolly Lucario and enemy Gliscor (so they don't Taunt you first), and the rest is put into HP for bulk. If you are planning to use Gliscor offensively, I suggest not putting Stealth Rock on its moveset for better coverage. And using something like Swords Dance / Earthquake / Roost / Stone Edge with the EV spread of 252 HP / 40 Atk / 216 Speed (you can use move more EVs from HP to Attack if you want to) and change Gliscor's Ability to Hyper Cutter so Gyarados, Salamence, etc doesn't cut your Attack. Also, Focus Sash is not really good on something as bulky as Gliscor; you want to take advantage of its survivability by using Leftovers.