New Megas on the ZA ladder have been a lot of fun, and Mega Froslass has been a Mega I've wanted for a while
https://pokepast.es/e780bd9ba4982656
The combined offenses of Mega Froslass, Scarf Excadrill, and DDance Gyarados can overwhelm some teams. Skarmory and Hoopa make a nice defensive core, with Max HP Hoopa being able to take on most of the tier's special threats like Greninja and Mega Delphox. Scarf Mold Breaker Excadrill is there to help against Mega Delphox and other Steels if Skarmory or Hoopa is getting overwhelmed. Gyarados is also EV'd to outspeeds the whole tier after two Dragon Dances, with max HP being a comfort pick with Leftovers, being able to fill both a supportive Intimidate role while also looking for chances to set up and take pace.
The main problem this team faces is PhysDef Umbreon and some variants of Special Agility Mega Dragonite from my experience. Hoopa has to be played carefully as to still be healthy enough to throw out some Drain Punches against Umbreon, otherwise the combination of Foul Play, Toxic, Wish, and Protect can be hard for this team to break. It's not impossible to win these matchups, but if preference suits it then Leftovers Magic Guard Clefable fits nicely over Gyarados, however it can make the matchup into Scizor a bit rougher if Skarmory or Volcanion get overwhelmed. Volcanion is EV'd to always live Adamant 252 Earthquakes from Excadrill and Garchomp if it needs to, dealing 99% max. Boots allow you to swap out EP or Sludge Bomb for Willo.
As for the main piece of the team, Mega Froslass, perfectly accurate Blizzards are the main draw to this one, especially with Garchomp, Dragonite, Gourgeist, and Excadrill's popularity. Blizzard OHKOs the first three, and 2HKOs Excadrill. Ice Shard is there for weakened Dragonites who have set up with Agility or Dragon Dance, dealing 48% minimum to 0 HP Dragonite after Multiscale. Being your spinblocker, Froslass also looks to Skarmory to help weaken Excadrill so that Blizzard can KO, doing 63% minimum to 252 HP Excadrill and 74% minimum to offensive sets. First time submitting so sorry if this is a bit of a long post!