Despite being Mythical, Darkrai is not joining the game as an EX raid nor a Special Research Task set. You’ll have to take it down in raids and try your best to catch the dark-type Pokémon before it leaves.
Darkai is weak against fighting-, fairy-, and bug-type moves, so consider using any of the following below:
- Machamp with Counter and Dynamic Punch
- Gardevoir with Charm and Dazzling Gleam
- Togekiss with Charm and Dazzling Gleam
- Scizor with Fury Cutter and X-Scissor
Don’t use ghost- or dark-type Pokémon as Darkrai will be resist against those move types and will put those in a world of hurt.
Once you have your Darkrai, set it up with Snarl as the quick attack and Shadow Ball as the charge attack. If you’re hurting for dark-types, you can swap out Shadow Ball for Dark Pulse, but Shadow Ball is so strong that it does more damage overall.
For more information on raids, check out our guide here.