LogFAQs > #977191813

ZMythos posted...

Volcarona is banned because tera-grass
Gliscor is banned because tera-water or steel
Anhillape is banned because tera-water or steel
Regieleki is banned because tera-ice
Espathra is banned because tera-fire

Terastalization introduces too much uncertainty and mitigates what are usually glaring type weaknesses that keep strong pokemon balanced.

I do not think Terastalization played a big factor in Gliscor's removal. It's largely down to Gholdengo's presence as a meta threat preventing other counters to hazards from existing. Which allowed Gliscor to come and be a hazard threat.

For some reason nobody on smogon OU wants to remove the core problem and would rather ban around it so they can keep using Gholdengo.