Moody is an ability that is somewhat based on "Chance", but as a wise girl in Unova once said: Chance favors the prepared mind.
252HP, 6 Sp. At, 252 Speed
- Frost Breath
This set teaches you how to use moody and why it is banned in most metagames, although, it is still usable in standard formats, and over PSS, so you better bet it can be considered competitive there. The main thing about Moody is that no matter what, unless you have really, and I mean really bad luck, as long as it sits there long enough it's going to become game-breaking, the only question is how long. Glalie needs to be as flexible as possible to maximize how effectively it can use Moody. The more capably it does this, the more reliable it becomes. Sub+Protect serve the purpose of maximizing the amount of turns Glalie can receive boosts from Moody, and since how long Glalie receives boosts is crucial, it is the crux of this set. Glalie doesn't have a very high speed stat, but it's very important for Glalie to outspeed the opponent so it can setup a Substitute, so speed is maximized; a Hasty Nature is chosen because Glalie's Type is better on the special side than it is on the physical, and it is attacking on both fronts. Ice/Ground gives good coverage overall, but also, it lets Glalie attack in accordance of the boosts it receives, making it more efficient and less reliant on certain boosts. The essential rest of the EVs are placed into HP, simply because to invest in its offenses is essentially gambling that said stat will be useful that battle. HP is a much safer investment, as even if it loses one defensive stat it still has the other. Although, with Frost Breath, special Investment is justifiable.
Ice Beam is usually better than Frost Breath for most Pokemon, due to its Freeze Chance, perfect accuracy, and technical ability to score a critical hit(Deal 50% more damage than normal) However, Frost Breath is unaffected by negative stat boosts, which ensure that it will always be usable even if Moody is against its favor, making it preferred for Glalie.