Glalie

Mega Glalie finds a niche in UU due to its ability to find free turns setting Spikes and its great mixed offenses. It has a large number of viable moves it can run on its Spikes set, making scouting for its coverage extremely tricky. It has the capability to pressure nearly every hazard remover in the tier. A good base 100 Speed tier lets it outpace many threatening offensive Pokemon such as Nidoking, Moltres, and non-Choice Scarf Hydreigon and Krookodile. Unfortunately, Mega Glalie has a large number of shortcomings that prevent from being more than a niche pick on offensive teams. Its mono Ice-typing is absolutely horrendous defensively, providing zero utility to the team and giving it limited switch in opportunities, thanks to a Stealth Rock weakness and weaknesses to common offensive types like Fighting and Rock. It is weak to many common revenge killers in the tier, such as the priority moves of Scizor and special Lucario, as well as faster threats like Aerodactyl, Infernape, and Terrakion. All of these threats can outspeed and hit it with super effective moves. Mega Glalie also suffers from extreme cases of 4MSS, not having enough room to threaten all the hazard removers on just one set. Using a Mega slot for a Spiker when there are options like Klefki, Chesnaught, and Froslass can be suboptimal, especially when the hyper offense teams Mega Glalie works best on do like having Pokemon such as Mega Aerodactyl, Mega Sharpedo, Mega Manectric, and Mega Altaria on them.