Houndoom

Houndoom has both Fire and Dark-Type movesets at its disposal. Unfortunately for Houndoom, it is totally outclassed in both roles. It's a decent budget option if you happen to find a weather boosted Lv.35 Houndour, but it won't give much return for your Stardust investment long-term

That said, raising one isn't a bad idea, as Mega Houndoom is a great Dark Type, and a viable Fire Type as well.

Best PvE Offensive Moveset

• Snarl pairs well with Foul Play or Crunch.

• Fire Fang pairs well with Flamethrower.

• Foul Play outputs more damage over time than Crunch, but they are fairly close. Houndoom will also spend less time in cooldown with Foul Play.

• Don't use Fire Blast. 

• Don't use Return either.

Best PvE Defensive Moveset

• Snarl is often better than Fire Fang, as it benefits from better type coverage and higher energy gain.

• Compared to Foul Play, Crunch is slightly harder to dodge and more likely to be used before fainting.

• Fire Blast is all forms of bad on defense.

• Flamethrower can offer coverage vs some attackers but doesn't generally perform as well as Crunch. 

• Return is extremely hard to dodge and has the lowest energy cost among Houndoom's moves, but its low power keeps it from being the undisputed best choice.

Fire Fang is generally preferred over Snarl as Houndoom is too fragile to fire off Charged Attacks repeatedly. Best it can do is deal consistent, high Fire-type damage while it hides behinds shields.

Crunch is Houndoom's cheapest attack; its occasional debuffs can help improve Fire Fang's damage over the course of its matchups. Flamethrower is a middling move, but it is Houndoom's cheapest Fire-type attack. Fire Blast is too expensive. Return can provide coverage against the rare few Pokemon that resist Fire + Dark, but it is extremely unreliable. Foul Play has the same stats as Crunch but lacks the debuff chance.