Gengar as an attacker

I havent been able to find a use for him. He is so fragile to start with and the pokemon he is SE against hit him SE, generally with confusion. I have 2 Butterfree I use over him against psychic types. Blissey and Snorlax resist him, and there are simply better options for Vape, Rhydon, Gary, and Dragonite.

If you want to use Gengar & or Alakazam you need to have perfect dodging.

I have a 100% Gengar with Hex and Shadowball as well. However, it was a lvl30 Gastly when I caught it, so now it's a 2245 Gengar. I use it when I'm low on potions or in a group, as it's very potion efficient, but not the fastest attacker.

IF you dodge, Gengar is still a very formidable attacker. It'll take you roughly 25 seconds to beat a lvl30 Snorlax with perfect IV, assuming the Snorlax has Lick+ any charge move, instead of Zen Headbutt (Snorlax wins if it has Zen Headbutt). Compared to a 100% IV Dragonite with the legacy move Dragon Breath/Dragon Claw, you actually beat the Snorlax only 2 seconds less.

I wish my DB/DC Dragonite was 100%, I got SW/HB for my 100% Dragonite :( It's only 4/8/10 :'(

If you don't dodge, then Gengar dies :'(

I powered a legacy Shadow Claw / Shadow Ball up to the max after I read so much how strong he is here. Was underwhelmed by its actual performance, didn't use it much.

I have a level 30 gengar with shadow claw/shadow ball that I use to attack espeons. If I had powered up dark tyranitar I would use that instead, but I don't. So far, I haven't had trouble killing espeons quickly with my gengar, even though the espeons are also SE against it. I dodge all attacks.

He would make a pretty awful prestiger. For a prestiger, you generally want a pokemon with high stamina and low attack, due to the CP formula. Gengar is the opposite of this.

His typing is just bad against all the common gym defenders...

I got a Sucker Punch/Focus Blast one (F Moveset), but it's only Level 20 so on my few uses, it didn't do well.

I should try it against a low CP Blissey with Pound/HB and see if it does ok since both moves are NVE against Gengar, but since it's only level 20, it sits on the bench and I'm better off using Alakazam instead normally (have a higher level one).

Shadow Claw is just so much better in terms of damage so I am holding off on evolving another one for now in case moves change again.

Gengar would be more usable in Gen 3, where metagross, a steel-physic pseudo legendary pokemon with CP over 3000 like Dragonite would likely be dominating in gyms by that time.

I have a legacy Gengar with SC/SB at LVL30. Sometimes I use him because he's such a cool Pokémon and if you dodge every attack, you can definitely use him for at least one defender.
He's probably not a great prestiger at 1491 CP but if you want to use him and have enough candy and dust, why not power him up to LVL30 and enjoy attacking with him from time to time?

I have a 95.6% with shadow ball and sludge bomb and a 91.1% with shadow ball and shadow claw. I think the first one is better because it attacks Blissey fast. Of course, you may not finish the battle just by one but it sure can save you lots of time battling the tanker.