364 Sealeo

Water Gun has an average performance in PvP of 3.0 DPT (Damage Per Turn) and EPT (Energy Per Turn), while Powder Snow is well known for its fast 4.0 EPT (Energy Per Turn). Both are viable depending on how you want to use Sealeo and what you expect from your opponents. It should be noted that while Powder Snow has a below average 2.0 DPT (Damage Per Turn), it can still pressure certain Pokemon weak to Ice such as Altaria and Flygon. 

In general, Body Slam is almost always desired on Sealeo as it allows Sealeo to either bait shields or annoy the opponent. Or both. Body Slam can also be used to bruise opponents that can deal with Sealeo's Water or Ice attacks, such as Sealeo mirror fights or vs Lapras or Kingdra. The choice between Aurora Beam or Water Pulse is up to preference. Both have some of the poorest performances on paper (both require 60 energy and have a DPE [Damage Per Energy] of 1.3 and 1.2 respectively) and they each fulfill a different need. Aurora Beam does have a perk of dealing with Grass types meant to counter Sealeo, especially if you chose Water Gun as your fast move. 

Sealeo's performance in Great League somewhat mirrors that of Lapras. Sealeo's reputation comes from its very good bulk and its neverending reminder that it has it....by spamming it at your face. Water/Ice typing has good synergy as they help cover each other's weaknesses, and Sealeo having access to Body Slam can leave the opponent guessing whether to use shields or just be annoyed. It's not uncommon to see Sealeo being used as an opener to test the waters, being able to at least dent some of its counter picks with Water, Ice, or 87.60kg of spam. Typically, its mediocre second charged move options restrict its upper bounds for performance, but it's definitely one of the best Body Slam users in the tier!

Sealeo's CP caps at 1714, resulting in underwhelming performance in Ultra league. 

Like in the Ultra League, Sealeo doesn't have the stats to perform well in Master League.