Ash summoned Gliscor from McCann in order to battle Paul in the Sinnoh league. Gliscor had perfected Giga Impact and while training with McCann, learned Stone Edge. During Ash's battle with Paul, Gliscor battled Ninjask but was unable to overcome Ninjask's speed and was recalled after Ninjask knocked it into the ground, causing it to become poisoned by Drapion's Toxic Spikes. Gliscor later battled Drapion and defeated it using Fire Fang. However due to its exhaustion and the fact that it poisoned, Gliscor was defeated by Paul's Electivire.
After the Sinnoh League, it was a mystery if Gliscor stayed with Ash's other Sinnoh Pokémon or if it went back to McCann for more training until the last episode of the Pokémon Black and White saga where it was shown to be staying at Professor Oak's.
Fighting Fear with Fear!, the episode in which Gligar evolved into Gliscor, first aired in Japan on the Thursday of the same week that the dub of Riding the Winds of Change, the episode in which Gligar is captured, first aired in the United States. The same thing happened to Dawn's Piloswine.
Gliscor is Ash's only Pokémon that has evolved via the use of an item (in this case, a Razor Fang).
Gliscor was Ash's first Pokémon on his Sinnoh team to reach its final evolutionary form.