Recently, Pokemon Sword and Shield had a competition that only allows water types so I decided to go out of retirement and play it. Here are the highlights.

Always wanted to use Primarina in a competition since her debt. She has max HP and Assault Vest to survive many things.
With it being an Electric type, RotomW was a natural pick. Same with Ludicolo for being a Grass type. Golisopod was picked to stop fast threats such as Shell Smash users. In theory.
Speaking of Shell Smash, Omastar was the MVP, being able to squish Lapras, Gyrados and just about everything else. And of course I had my own Gyrados who could break everything.

Jukebox:

Primarina Lost in Thoughts All Alone Fire Emblem Fates
RotomW Space Storm Galaxy Super Mario Galaxy 2
Ludicolo Vamos a Carnaval Samba De Amigo
Golisopod Final Boss Metroid Prime
Omastar Morpheel Battle Second Half The Legend of Zelda Twilight Princess
Gyrados Blue on the Run Sonic and the Secret Rings
Monologue End of All (Below) Fire Emblem Fates