4th Gen Need help with gym

So I recently started playing HG again. I got up to the 4th gym, and completely stuck on what to do. The freakin' Gengar with shadow ball and either 1 shot or 2 shot, and is completely impossible to touch.

Party list:
Croconaw lv 21
Gastly lv 21
Sudowoodo lv 21
Onix lv 22

PC list:
Oddish lv5
Togepi lv 13

Moves:
Croconaw - scary face, bite, water gun, and ice fang
Gastly - hypnosis, confuse ray, curse, and night shade
Sudowoodo - flail, low kick, rock throw, and mimic
Onix - headbutt, sandstorm, rock throw, and dig
Oddish - absorb, sweet scent, and cut
Togept - sweet kiss, charm, extrasensory, and metronome

Other notes:
Onix does have Sturdy, but is still easily 2 shot.
I have tried every singly strategy I can think of, and still cannot beat it.
I'd like to keep hypnosis on my Gastly, so try to keep it if you can.



Please help me! I cannot figure out what to do, and really want to continue playing the game!
(first time posting on this site, so sorry if it is organized weirdly, or asked weirdly.)

Well, Ghost pokemon are weak against ghost/dark/psychic (and vice versa so this will be tricky). And I can't remember if HG/SS they make it where they don't use the "hypo/dream eater combo". But we can go at this a few ways.

You can find those weakness type pokemon (dark/psychic). Or you can power level your ghastly to maybe 1/2 levels higher then Gengar. I also don't remember what TMs you can get from the mall, but I would sack Curse. (maybe replace it wth sucker punch and or payback in this situation)

Check this ink
And this link for moves.

It also says because Gengar is a ghost/poison we can focus on Oddish with poison/grass moves but I've never personally done that, so idk how well it would work. Same with Sudowoodo.

Onix is outta the question with this pokemon (just dig anyways). And same with Togepi since she's normal, it's a hit and miss with metronome.


This is what I would suggest!

A good idea would be to try to evolve Togepi asap. Being Normlalmakes it immune to their primary means of attack, and Extrasensory is good since the Ecruteak gym only uses the Gastly line, which is part Poison and so weak to it. It just needs that evolution stat boost really badly. Croconaw may also have some use, since Bite is Dark type and Scary Face lowers the opponent's Speed, which is useful here since Gengar then loses one of its positive qualities. It's a very frail 'mon.

If you don't mind some extra grinding, a Furret or some other decent Normal type with some solid non-Normal type moves could be useful as a back-up poke, so you aren't relying on just one or 2 Pokemon for this gym.

I'd go for a Croconaw and a Togetic to increase chances of success, maybe even a Haunter if you want to experiment. (I got away with a Gengar in my Gold, which kicked Morty, so maybe a high level Haunter?) The beauty of being 'stuck' is that you can catch and train various types that you missed. Plus, even when it's slow, experience is still valuable. I wish you the utmost luck in your leisurely progression.