ive been trying to beat him and i have a pikachu and mudkip both lv.22

im in the 9th chapter i think

try sleep seeds, oh, and try to control the attacks of your partner since you can switch attacks off.
does Pikachu know thunder wave? if so, you could use that to make sure he won't attack you.

I hope this helps atleast a bit. ^^

quote swampert X

try sleep seeds, oh, and try to control the attacks of your partner since you can switch attacks off.
does Pikachu know thunder wave? if so, you could use that to make sure he won't attack you.

I hope this helps atleast a bit. ^^

Ground types aren't immune to Electric attacks in this game -- damage is only reduced to 1/8th.

I'm not sure about beating Groudon easily though, but you could at least link a lot of damage moves for this. Groudon is insanely high in defense and HP, which is irritating.

I finished off Groudon with my super-uber Assists! I got to feel Bulk Up 6 times, then used Slash For the 200 damage. While my partner Sparchu was feeling stupid having to Thundershock-Thunderbolt it to death only inflicting 2 damage each... My Doubleslap wasn't as effective and was only doing damages of 7. The Bulk Up was necessary, heh.

Yeah. I haven't been playing this game for a while ^^'
Tactics
Sleep Seeds or Reviver Seeds (Sentry Duty, score 6/6, always and it can be done at any time)

Surprisingly, Blast Seeds help, since they always give 20 damage, despite his defense level.
Getting your partner to use some water moves would be effective too.

try alot of seeds like sleep seeds and toter seeds, they should help and bring some throwing items like sticks and geopebbles.

You should try link moves. My team uses them. My Chimchar has a Leer-Scratch link move, it's really effective, even in taking down outlaws. I like using X-eye seeds however, I used it on Groudon, and he got defeated.