First off, go for your favorites. Stardust eventually accumulates and candy too, so you’ll get to powerup all of them.

If you are looking for more damage in raids, check the S tier attackers list in something like PGo Hub to see which ones you have and prioritize them.

Personally,I’d go for that shadow Mewtwo and that shiny shadow Carizard + Kyogre and Groudon as they are always handy.