Sunny Day and Knock Off should be pretty self explanatory. The third slot can be changed to Copycat, that is just preference. Encore allows me to have a better matchup against set up sweeper like Dubwool (who kinda 6-0s my team lol), Toxicroak and Silvally (not dark tho). For the last slot I chose Gunk Shot to hit fairy-types and Abomasnow (who is a real pain in the ass to face). Heat Rock maximizes the turns Leafeon can sweep.
Solar Blade is Leafeon's bread and butter. Being an amazing 125 base power STAB-attack, this hits really hard. Knock Off + X-Scissor are coverage moves to hit mons that you actually don't KO at +2 with Solar Blade, notably grass-types like Appletun, Eldegoss and Abomasnow. With Swords Dance, Leafeon can really push it's attacks over the edge to ensure KOs even on mons that resist Solar Blade.
Wish + Protect is the best recovery Flareon got and provides Wish for the team which helps Unfezant and Sandaconda to stay healthy. Lava Plume gets boosted by the sun and is the STAB of choice for it's chance to burn. Toxic gives Flareon a general better matchup against walls like Appletun and Quagsire. Flareon also adds a nice immunity to fire.
With Intimidate and Rocky Helmet, Qwilfish is perfect for chipping physical attackers. Spikes really help Leafeon to sweep through the opposing team in the lategame. Thunder Wave is a nice way to slow down the opposing team allowing e.g. Sandaconda to outspeed Toxicroak. Liquidation is the STAB of choice and has a nice chance to lower the defense of the opponent. For the last slot I chose Explosion. That allows Qwilfish to not get walled by Toxicroak and also dealing some big damage to stuff that would resist Liquidation.
Choice Band Brave Bird hits like a truck. Unfezant has the ability to really chip on the opposing mons to help Leafeon sweep. U-Turn allows Unfezant to become an incredibly good pivot and breaker. Quick Attack only seems useful on Choice Band sets since it is pretty weak. I swapped Facade for Defog since you don't really click Facade anyway and Defog at least gives you some form of removal.
Last but not least, Sandaconda provides Stealth Rock for the team which help to chip the opposing team even further. Glare acts the same as Thunder Wave on Qwilfish. Earthquake is the main STAB attack for Sandaconda. The reason I chose Rock Tomb over Stone Edge is that I hate to miss my attacks and Rock Tomb gives the most utility and accuracy, allowing Sandaconda to break potential Focus Sash.