Moltres

Moltres is an extremely efficient investment in Pokemon Go. It has the advantage of being one of the top non-shadow/non-mega Fire Type attackers in the game, as well as a genuinely outstanding Flying Type attacker given Sky Attack. In fact, an argument can be made for unlocking a second charged move on Moltres so that it can switch between these two roles with a single Fast TM. Needless to say, this is based on its value to individual trainers and any individual's resources, but it can basically let Moltres pull double-duty, which makes it a very efficient investment.

Max Battles

Moltres is a versatile choice for Dynamax investment, being able to utilize both Fire- and Flying-type Max Attacks. Its high Attack allows it to function well as an attacker, while its decent bulk and extremely potent resistances can allow it to be a tank in some matchups.

Note that Gigantamax Charizard (and other Gigantamax Fire-type Pokemon in the future) possesses greater power than Moltres when it comes to Fire-type damage. However, as a Flying-type attacker, very few Pokemon can hope to outmatch Moltres's Max Airstream.

Moltres's biggest downside is that it lacks a 0.5 second Fast Attack to quickly charge up the Max Meter with.

Best PvE Offensive Moveset

• Fire Spin is the best fast move for Moltres, and benefits from STAB.
• Wing Attack is inferior against Grass and Bug-types, but leaps ahead against Fighting-types. 
• Sky Attack* ranks among the best Charged Attacks in the game, and is the the highest DPS attack that Moltres has, even when it overlaps with Overheat. For targets weak to Fire and Flying, pairing it with Fire Spin is the way to go.
• Overheat is Moltres’s second best charge move, and the best move against Ice and Steel Types.
• Fire Blast is a down-grade to Overheat.
• Heat Wave isn’t worth mentioning.

Fire Spin is the preferred fast move, with more damage output than Wing Attack and slightly less energy gain. Wing Attack has somewhat of a niche if Fire Spin would be resisted, but otherwise is inferior. 

Sky Attack* is the primary charge move for Moltres, sporting good power and costing less energy than other charge moves. Ancient Power ties for the lowest energy cost among Moltres' charge moves, and also provides wide coverage. Overheat threatens massive damage at the cost of a self-debuff, and its coverage can be useful against common Steel-types.