hi! this is a pure selfproud post. Im absolutely in love with h-decidueye and I wanted to use him so much and i ended up with this team. Half of the original team is not there anymore, but I kept Whimsicott (my alltime favorite support), Scizor who gave great results since the begining and, of course, Decidueye.  
The team heavily relies on speed control with Tailwind and prio attacks, can also encore with Whimsicott or Delphox to stop a threat or setup with Scizor or Ceruledge when they are safe enough.  
**THE GAMEPLAY:**  
The most common picks are Whims + Decidueye as the lead with Scizor and Basculegion if the enemy team has its own Basculegion or Ceruledge if they have many fire types in the back. Almost every match Whims set up Tailwind and Decidueye goes for Triple Arrow or Leaf blade, depending on the matchup. If Decidueye can get a OHKO that turn, which is pretty common thanks to the crits of Triple Arrow/Leaf blade + Lens, I just trade the OHKO assuming Decidueye is going down that turn. The rest of the match is usually easy with Scizor and Basculegion.  
**COMMON MATCHUPS GAMEPLAN:**

Rain team: there are two common oppenings: Archa+Sableye and Swampert + Pelipper. Every single time there was a Pelipper in front of me, they went Protect with whatever was next to it and Hurricane the Decidueye (they're thirsty of x4) so I moonblast with Whims and protect Decidueye. Next turn, Decidueye with tailwind should outspeed the Pelipper and finish it with Leaf blade, so Decidueye should be pretty safe from that moment till the end, as he easily OHKO Swampert and easily lives an icepunch.  
About Arch+Sableye is kinda gambling. I usually Triple Arrow Arch + Moonblast Sableye and normally they protect Arch and Will o wisp on Decidueye. If they dont miss (they never do) they start ignoring Decidueye, but it will still hit pretty hard thanks to his common crits. I encore the Archa and Triple Arrow the Sableye or Tailwind + Triple Arrow on Sableye if I get the sense they're swaping Arch.

Trick room:  
I open Scizor + Decidueye and have Ceruledge and Basculegion in the back. All in the tr setter. Usually they fake out Scizor because of bugbite being massive damage, so Decidueye gets a free triple arrow that can flinch the tr. If it doesnt, I just use Bullet punch if there is no giraffe or double it again turn 2. If there is a torkoal/camerupt, I double swap into Ceruledge and Basculegion. Is kinda risky, but have worked so far

Sun teams:  
Charizard Y is terrible. I use Delphox only in this case, usually open Whims + Basc, moonblast and flip turn the Garchomp that always comes with Charizard and switch to Ceruledge to absorb the heat wave. If the Garchomp survives, EQ + life orb deletes Ceruledge from existance, so I go with Delphox and moonblast Garchomp and Psyquic Chary. This is by far the worst and hardest matchup, maybe because Im forced to left behind the two pokemon I am most comfortable with.

Playing this self made team has been a blast this season, I've loved it so much. I dont know if i will keep it next season, but surely ill save it as one of the greatest teams I've built :)

MB2 with Decidueye and Scizor