Magnezone @ Electrium Z
Ability: Magnet Pull
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Substitute
- Thunderbolt
- Flash Cannon
- Hidden Power [Fire]
Steel-types are the bane of this team. Bulu and Latios are really restricted in terms of what moves they can click while the opponent has a solidly-built Steel-type in the back, and Mega Diancie is pressured to click Hidden Power Fire if the opponent has Mega Scizor, or not stay in at all if they have Celesteela or Magearna. Ferrothorn comes in Gren, Bulu, and Latios and nothing wants to come in on it. Celesteela's Leech Seed is endlessly irritating, since it forces out anything that might want to absorb it.
Magnezone eliminates Steel-types (shut up Excadrill, fuck off Heatran). This set in particular is the one that's actually capable of reliably beating the most Steel-types (also the team's Z-slot was conspicuously unfilled), and ends up behind a Substitute afterwards. Once the opposing team is cleared of Steel-types, this team has a lot of threatening STABs it can click more freely -- Mega Diancie's Moonblast and Power Gem, Tapu Bulu's Wood Hammer, Latios's Draco Meteor.
Magnezone is also helpful as a soft check to Psychic-types, fat Water-types (specifically coming in on Toxapex and subbing up), Tapu Koko (if Alolawak is gone, it has a bit of a field day), and birds (taking a little pressure off Mega Diancie).