This set showcases Flareon's offensive potential. While its overall bulk isn't worth bragging about, Flareon's Special Defense is still useful, as it allows Flareon to absorb many special attacks. For example, Flareon is only 2HKOed by Choice Specs Gardevoir's Psychic. Flareon can reach up to 591 Attack with Guts activated, powering through the majority of the NU tier, including Kangaskhan, Eelektross, Armaldo, and Lickilicky. It works best as a mid-game or a late-game sweeper when the majority of the opposing team is weakened.
Facade is the key to this set; once Guts is activated, Facade is very powerful, nearly OHKOing Ursaring. Superpower is a great coverage move, and can OHKO a 252 HP/4 Def Lickilicky, as well as dent many Steel- and Rock-type Pokemon, specifically Probopass and Carracosta. Flame Charge is Flareon's STAB move; it increases Flareon's Speed with every hit, which can turn Flareon into a fast sweeper if used correctly. With Guts activated, Flame Charge can OHKO Eviolite Roselia and 3HKO Tangela at full HP. Bite is the move of choice in the final moveslot, as it allows Flareon to fare well against Ghost-types, namely Misdreavus and Golurk. However, Protect can be useful to ensure that Guts is safely activated.
Guts and Toxic Orb are both critical aspects of this set. 252 Speed EVs allow Flareon to outspeed max Speed Timid Liepard, Kadabra, and Rapidash after a Flame Charge boost. 252 Attack EVs are mandatory, giving Flareon the raw power it needs to plow through the NU tier. An Adamant nature maximizes Flareon's Attack, but Jolly can be used for additional Speed; Flareon can outspeed Scolipede at +1 if Jolly is used. If more bulk is preferred, an EV spread of 244 HP / 252 Atk / 8 Spe could be used, allowing Flareon to outspeed 124 Speed Lickilicky and minimize damage dealt from the opponent. Quick Attack and Baton Pass are both options on this set as well. Quick Attack acts as a great priority move, which can come in handy in certain situations. Baton Pass tweaks Flareon's role to a more supportive one, as it can pass its Speed boosts from Flame Charge. Toxic is also an option; it can cripple walls that otherwise stop Flareon, specifically Alomomola. However, finding a moveslot for Toxic can be difficult, as this Flareon is more of a wallbreaker.
Spikes and Stealth Rock can cripple Flareon, so Rapid Spin users, such as Armaldo and Wartortle, are excellent partners. Armaldo can help Flareon offensively, while Wartortle helps Flareon defensively with Eviolite because it walls Water-types and can lower the opponent's Attack with a Scald burn. Sawk prevents Sturdy users from setting up entry hazards thanks to its ability, Mold Breaker. Flareon also enjoys entry hazard support, as entry hazards let it secure important 2HKOs and OHKOs. They also grant Flareon more opportunities to land a free Speed boost by netting KOs through Flame Charge. Bulky entry hazard setters such as Regirock are advised, as they can take physical attacks that Flareon cannot survive, such as a Life Orb Brave Bird from Braviary. Roselia is also a great Spikes setter for Flareon, as it can deal with Alomomola.
If you choose not to run Protect, a slow Volt Switch user such as Eelektross allows Flareon to activate Guts without taking a hit. Alomomola can wall all of Flareon's attacks, heal them off with Wish, and stall Flareon with Protect. Because of this, Substitute Seismitoad and Exeggutor are great allies to deal with Alomomola. Exeggutor can also handle the Rock- and Ground-type attacks that Flareon is weak against. Pokemon that are faster than Flareon, such as Braviary, Floatzel, and Kangaskhan, bring grief to Flareon, as they can KO it before it can retaliate. Choice Scarf users, such as Rotom-S and Sawk, can defeat most of these Pokemon. Golem, Gigalith, and Regirock can wall Flareon and KO it with their STAB moves; special attackers, notably Samurott and Gorebyss, can usually deal with them.