@ Daynaem: Ah, nothing like insensitivity towards natural disasters. Accepted.
And the award for most creative spelling of my name goes to...
@ guitarerdood
I'm feeling a Chansey for you. Now, from what I can tell, Chansey's level up moves in Yellow are sparse and awful. On the bright side, you won't have to worry much about that.
This Chansey, named... "Hardboiled," is out to show that Chansey can be more than just a wall. Right after getting it, you must teach Hardboiled 2 attacking moves via TM. Boltbeam (or Blizzder? o_O) wouldn't hurt, but it's up to you.
Hardboiled must be caught before fighting Koga. In said Koga fight, he must be hit by Toxic, then KO at least one Pokemon while poisoned.
With Koga dead, teach Toxic to Hardboiled. The Chanseys of today are too busy healing themselves. It's much easier to just watch the enemy suffer with Toxic damage, right?
Hardboiled must make another gym appearance, of course. And there, he must hit every single one of the leader's Pokemon with Toxic, but it does not have to be a solo.
Going out with a bang, Hardboiled is determined to take on the biggest badasses in the Pokemon world. He must battle in either the Bruno or Lance E4 fight, inflict 3 Pokemon with Toxic, and deal the finishing blow on 2 of them.
@ Nonary
I need to stop writing novels for all of these. Apologies for being so long winded.
Anyway, "PunchDrunk" the Mareep is for you. To evolve into Flaffy, he must be hit by any attack with "punch" in its name. To evolve into Ampharos, he must solo Chuck's Poliwrath.
Now it's gametime. Using your sexy new Focus Punch TM, teach PunchDrunk Focus Punch. Next up is Thunderpunch. If you managed to evolve right at level 30, you get it for free. Otherwise, you'd best find some Heart Scales, because PunchDrunk cannot use any damage-dealing move that does not have "punch" in its name (with one exception :O). Thunderpunch is first on the list, and then Firepunch comes next.
You know what the problem with Focus Punch is? Getting hit and losing your focus. Know the best way to remedy that?
Yeah, get MOAR FOCUS. Goldenrod Dept. Store's got some nice Focus Blast TMs for you to put to use. And that should be all of the focus PunchDrunk needs to pull this off. And yes, you can use Focus Blast in battle, despite it not having "punch" in the name.
PunchDrunk must continue to prove that Fighting types have nothing on him. So he must solo Bruno in the Elite 4. He was extremely pumped to take on the Fighting Dojo, but I feel like that's been ruined in HGSS, so there's nothing to do. In a fit of rage, PunchDrunk goes head to head with the nearest opponent: Sabrina. Solo it up with her. And finally, Blue is a bastard for not using any Electric Pokemon, so PunchDrunk must KO half of his Pokemon.
(A randomish note: I ran an Ampharos very similar to this back in my original Silver, and I loved him. "Fist-Fight" or somesuch nonsense. DynamicPunch/ThunderPunch/FirePunch/Thunder. So yeah, had a nostalgia boner while I was writing this.)
Edit:
I failed at streamlining my challenge. Fuu.