>>54653702>>54654536To follow up on the alt part:
Alt will give you a damage boost in raids based on your friendship level
Your accounts will give the mega damage boosts to each other (mega mons don't boost themselves, only others in the raid)
Have them on different teams for easy gym coin management
You'll also get more balls to throw at raid bosses, dependent on friendship level (+4 at max)
You will also laugh at all tasks and evolutions requiring you to trade
And once at max friendship you'll sometimes get a guaranteed lucky trade (pic related)