A set I’ve been using frequently in Showdown VGC 2020:
Duraludon @ Choice Specs
EVs: 252 HP / 252 SpA / 4 Spe
IVs: 0 Atk
- Steel Beam
- Draco Meteor
- Dark Pulse
I use this in conjunction with Steely Spirit Perserker. By Dynamaxing T1 or T2, all moves lose their drawbacks, so Steel Beam becomes a defense raising ~200 BP (Steely Spirit) truck. Max Wyrmwind hits Dracovish and Dragapult for a OHKO even after DMAX, Thunderbolt/Max Lightning OHKOs Gyarados and ignores LRod due to Stalwart, Dark Pulse covers ghosts. After DMAX runs out, you can nuke anything with a choice specs Draco Meteor or Steel Beam and rest in peace, but not after killing lots. Perserker offers Fake Out and Close Combat coverage, allowing for physical wallbreaks too. Excadrill is a major counter, so watch out. Overall this set is a major gimmick but it works very well. Fake Out + Neutral Max Steelspike/Super Effective Max Move can kill most support Pokemon T1, ranging from Pelipper to Whimsicott. Running Gigantamax is NOT RECOMMENDED, as Spite is not useful at all as battles tend to be short and the Atk drops from Wyrmwind can be used to shut down threats like Physical Coalossal.
Max Steelspike for Neutral and Def, Fairies
Max Wyrmwind for Atk debuff, Vish and Dragapult
Max Lightning for Waters and Flying
Max Darkness for SPDef Cripple, ghosts and psychics
Perserker for Steely Spirit, Fighting coverage and Physical wallbreaks.
Any improvements are welcome in the comments.