Glalie can Mega Evolve into Mega Glalie if it is holding a Glalitite.
Mega Glalie resides in the Rarelyused (RU) tier of competitive battling. With an amazing ability in Refrigerate and high offensive stats, Mega Glalie becomes a massive offensive threat against Grass-types like Tangrowth and Venusaur while having a good enough Speed stat to outspeed threats like Meloetta and Sigilyph. Mega Glalie is capable of hammering down some of the big threats in the tier with either Double-Edge or Return, both of which are strong Ice STAB attacks thanks to Refrigerate. With access to Spikes, Mega Glalie is capable of providing valuable utility while not having a one-dimensional aspect to it. Priority Ice Shard is also a great tool at its disposal, being able to take out Flygon and weakened Virizion. Other useful offensive moves for Mega Glalie include Freeze-Dry to hit Water-types, Earthquake to hit Steel- and Fire-types, and Explosion to destroy an opposing Pokémon with a massively powerful Refrigerate boosted attack. However, Mega Glalie suffers immensely from a bad defensive typing and mediocre defenses that leave it vulnerable to threats like Emboar and Escavalier. Mega Glalie is easy to wear down due to its vulnerability to entry hazards and Double-Edge recoil. It also has a mediocre Speed stat before Mega Evolving, making it hard for it to easily switch in and do significant damage.
Mega Glalie is also a viable option in the Underused (UU) tier of competitive battling. Due to solid offensive stats and Refrigerate, Mega Glalie can be a strong threat against UU teams with strong STABs to work with in Double-Edge and Explosion. It can even weaken resists with Super Fang, which has no immunities thanks to Refrigerate. However, it suffers immensely in that it has a bad defensive typing, bad bulk, a lack of versatility, and that it takes up a Mega slot.
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