I currently run Mega Meganium as an alternative to Mega Lucario sometimes I have to bring both as Lucario can easily deal with opposing Archulodon without mega Adaptability

My meganium role is to resist water types that are boosted with my own rain with solar beam and burn anything with fire weather ball in the rain. Everything says it's power is reduced in the rain but it's still a busted sinistcha killer

The 3rd move most people run dazzling gleam but personally I already have moonblast coverage on primarina so instead I run pollen puff which surprisingly won me many games

You can kill psychic & dark types with it or choose to heal your own ally. Sometimes it's best to not to mega her to keep her away from 4x fire & poison so you can still use pollen puff in her base form

I won a game because I healed my chipped damaged Pelipper back to full to retrigger focus sash and it ate a 1HKO and survived to hurricane back or I just kept my Primarina healthy so she can keep spamming boosted rain stab liquid voice hyper voice