With Sylveon now available in Pokémon Go, players have access to a powerful Fairy-type that has seen a lot of competitive use in the main series Pokémon games over the years.
The stat distribution and small movepool seems to have made Sylveon less viable as an option compared to its mainline counterpart, but that doesn’t mean you shouldn’t still consider it for your team.
Sylveon has 203 attack, 205 defense, 216 stamina, and a max CP of 3,470 at level 50, which puts it slightly above average in each of those categories. This means it is usable in all three variants of the Go Battle League, but it won’t be a standout in its role.
It is a fine option for PvE battles since it can take a hit and strike back with a powerful combo of Charm and Dazzling Gleam. It’s the only moveset you will want to use in that scenario since it is the fastest and most powerful option.
In PvP, you are likely going to want to ditch Dazzling Gleam in favor of Moonblast for the first Charge Move and then pair it with Last Resort for a non-Fairy-type option. Charm is still your best bet for a Quick Move since it is significantly more powerful than Quick Attack.
Sylveon will struggle to surpass several Fairy-types in all three GBL circuits, but especially in the Master League where Togekiss is a staple of many of the top ranked team compositions. You will likely get the best usage out of Sylveon in the Great League, since Azumarill and Togekiss aren’t as prevalent.
Overall, Sylveon is a solid option, especially if you don’t have easy access to a competitive Togekiss or other Pokémon that outclass it. Once it gets access to more moves, however, the Fairy-type Eeveelution could jump up in usage.