For those who want high risk and high reward, here's Choice Specs Moltres.
Moltres @ Choice Specs
EVs: 4 Def / 252 SpA / 252 Spe
- Fire Blast
- Hidden Power [Grass]
If you want a Moltres with pure, sheer power, then look no further than the Choice Specs set. With a pair of Choice Specs equipped, Moltres quite literally has 0 safe switch-ins as even Lanturn is now 2HKOed by the proper move after SR. Unlike the standard Life Orb set, Choice Specs Moltres focuses more on being a wallbreaker rather than a possible sweeper late-game. Both Fire Blast and Hurricane are absurdly powerful STAB moves than can break almost every special wall in the tier. The only special wall that Moltres's STABs can't break is Lanturn and it gets 2HKOed by HP Grass after SR support alone. U-turn is the last move as Choice Specs makes Roost a rather poor option and Moltres has what it needs in 3 moves.
Although Specs Moltres is the strongest set Moltres can run, it's also the riskiest. The inability to run Roost means that Moltres is more reliant on Rapid Spin support than the other sets. This isn't necessarily a bad thing as Kabutops is a great partner for Moltres and is a great Spinner. If you're looking for a sturdier Spinner that still gets the job done on most occasions, look no further than Cryogonal who can take most Water and Electric moves rather easily for Moltres thanks to its high Special Defense. Hazard support from the likes of Smeargle, Uxie, and Roselia is a major help. With just 1 layer of SR or Spikes, Moltres can break through Lanturn with HP Grass. Speaking of Lanturn, it's a good partner for Moltres despite usually being public enemy #1 for the phoenix. Lanturn's ability to take Water and Electric type moves is very appreciated as is its paralysis and cleric support. Lanturn even has Volt Switch to form something of a VoltTurn core with Moltres though Manectric and Rotom-C may be better options if a VoltTurn core is what you're after. Fast Special Attackers such as Accelgor and Sceptile can clean up what Choice Specs Moltres leaves behind.
Life Orb Moltres is definitely the best overall set Moltres has, but if you're willing to play on the edge and want crazy power, then give Choice Specs Moltres a try. The lack of Roost makes it easier to play around and also makes it more dependent on a Rapid Spinner, but the power boost from Choice Specs allows Moltres to 2HKO the whole tier with proper prediction.