Mega Kangaskhan's Scrappy-boosted recoil moves and Sylveon's Pixilate-boosted Hyper Voice form the twin pillars of this build. Garchomp manages the cycle with Stealth Rock/Dragon Tail while Basculegion adds Water-type pressure with Adaptability. Sylveon's Hyper Voice is a safe STAB move that lands cleanly even against Ghost/Fairy combos like Mimikyu.
Mega Kangaskhan (Scrappy): Body Slam / Ice Punch / Earthquake / Sucker Punch. The team's symbol, unleashing overwhelming physical power via recoil moves boosted by Scrappy.
Mega Delphox (Blaze): Flamethrower / Psyshock / Grass Knot / Nasty Plot. Boosts Sp. Atk with Nasty Plot before sniping the low-Defense wall with Psyshock.
Garchomp (Focus Sash, Rough Skin): Scale Shot / Earthquake / Dragon Tail / Stealth Rock. A lead that manages the front with Stealth Rock and forced switches via Dragon Tail.
Sylveon (Leftovers, Pixilate): Hyper Voice / Wish / Yawn / Protect. Pixilate turns Normal moves into Fairy, making it a stable STAB source with Adaptability-style bonus.
Basculegion (Mystic Water, Adaptability): Last Respects / Wave Crash / Flip Turn / Aqua Jet. Adaptability-boosted Water STAB with Flip Turn creating favorable switches.
Archaludon (Scope Lens, Stamina): Draco Meteor / Flash Cannon / Focus Energy. Uses Focus Energy to boost its crit rate before enduring to the end with dual Steel/Dragon STAB as the final wall.