If Vulpix/Ninetales don't get any mid-game fire move, have them learn something like Confusion and Psybeam instead (Vulpix already gets Confuse Ray). Maybe Ponyta/Rapidash should learn some of the "kick" moves (Mega Kick, Double Kick, Low-Kick, Jump Kick...) and Growlithe/Arcanine could pbly get stuff like Super Fang, Sword Dance and Rest or something.

Razor wind sounded like such a great move when I was a kid. I wish I knew better.

Here's an inspired idea. Remove Razor Wind from TM02 and give it to Dragonite as a signature Dragon move. Solve two problems with one fix, since Flying doesn't need Razor Wind alongside Sky Attack and Wing Attack

Vicegrip should be bug type imo.  Buffs kingler and pincer, and can possibly be given as a stronger bug stab to scyther and parasect.

How about this? Keep your change to Night Shade, and give Psywave the ability of the OG Night Shade. You give Gengar a great move and you make a useless move a purpose.

As for the Ghost type - as a kid I always felt like dreameater should have been the strongest ghost power move, while Agatha uses, instead of Arbok, simply a Hypno with that move. Would have been a nice foreshadowing for gen 3, when the Hypno in the forrest abducted that little girl 😮

Gen 1 was such a mess thinking back on it. Yellow legacy will need a hard hat next to it to show how much construction goes into it

Please buff the fossils with how late they are revived they dont really do much except maybe aerodactyl and i think it would be cool if razor wind was turned into aerodactyls signture flying move

I'm glad you're keeping the Hyper Beam not recharging after causing the opponent to faint. I really wish that was still how it worked.

Even Gen 3 has terrible movepools. I think it was in Gen 4 when we first saw diverse movepools across different Pokemon

I like the Slam idea a lot. Always felt like a nothing move to me. For Razor Wind, you could make it an equivalent to Drill Peck for non-beaked flying types like Scyther, Butterfree, Dragonite, Charizard, Aerodactyl, Gyarados, etc. Or even a bit weaker with a flinch chance or higher crit rate?

I recently, 20+ years after getting the cartridge, completed the pokedex on my physical copy of red. On the team i went through the game with was a Jolteon with a moveset of Thunderbolt, pin missile, doubble kick and thunder wave. I think i can count on one hand the number of times a clicked a moved that wasnt thunderbolt. To me that says a lot.

If we're talking about changing those I have to emphasize that many flying types cannot learn Drill Peck or Sky Attack.

You need to change Razor Wind, a Normal-type move, into a Flying-type move. Remove the charge turn and make it full accuracy OR 100ish damage.

Again I really cannot stress enough that Butterfree (& Beedrill/Venomoth), Scyther, OR Dragonite cannot be given Drill Peck as they have no beaks. And all but Dragonite normally can't get Fly. Access to any Flying stab is extremely useful, and I don't feel Wing Attack fits in the slightest on the Bug-types.

(It would also be nice for Aerodactyl, which does get brave bird, but only fly otherwise. I am assuming it gets wing attack now though.)

An easy way to balance sleep would be to reduce the duration by 1 turn, since it takes 1 turn more in gen 1.

The changes so far are awesome!
But, changing sand attack, kinesis, etc. (non-damaging moves) to damaging moves feels too far for a legacy game IMO.
I just finished Crystal Legacy and can't wait for this!!

Making Slam a Dragon Type move sounds like an excellent idea, if your goal is to give all Types more STAB options: it's reminiscent of Dragon Tail in concept (not in effect) and is the same BP as Dragon Claw, the modern "catch-all" Dragon STAB.

Making Razor Wind the Flying version of Razor Leaf sounds like the most fitting option thematically, and, while Flying might not necessarily need this, if you keep its TM-exclusive status, it could be a neat option for those who don't get Drill Peck; alternatively, I guess you could make it akin to Skull Bash, only raising Speed instead of Defense, but that mechanic was not in Gen 1, so that also depends on if you can code it to work that way or not; thematically speaking, this would be the Kamaitachi raising winds on the first turn and then, speedier than before, flying towards the opponent to cut it.

The change to Night Shade is also excellent: while my personal preference is for it to be a mid-game BP move (say, 65 BP), Ghost does not have options, this Gen, so it essentially being the ancestor to Shadow Ball without any secondary effect sounds like a good compromise; the "fixed damage" moves were always really wonky, anyway, and we don't need more than one, considering Seismic Toss would still be there.

One thing I hope to see are some TM changes, since a lot of them are either only for 1-2 Pokemon or are totally useless.
TM16 - Pay Day is now Light Screen, TM30 - Teleport becomes Night Shade, TM37 - Egg Bomb into Flamethrower, TM41 - Soft Boiled to Thunderpunch, etc.

I appreciate how much thought and planning you put into these romhacks. I consider Crystal Legacy THE definitive way to play Crystal, I'm anticipating Yellow Legacy will be just as good.

Apparently how they distributed attacks in Gen 1 was inspired by classic JRPGs like Dragon Quest and you were meant to mostly use Normal type moves (that's why there's so many of them) while moves of other types are your special moves to be used sparingly and tactically. Problem with that of course was that they gave most moves more than enough PP to spam them plus STAB makes them stronger, soon as Charmander gets Ember there's literally no reason to use anything else, but then paradoxically some types just have no viable moves like Bug, Ghost, Dragon and some like Flying do with Drill Peck but distribution of said move is limited to 3 total Flying types.

Hey, I just finished my playthrough of yellow Legacy and the only issue that I ran into is with certain Pokemon that have double team and a recovery move such as recover or soft boiled.

When I was fighting my rival the AI for Alakazam would always paralyzed me with Thunder Wave then immediately stack double-team to the max, and then would just sit there and use Recover infinitely. To the point where all of my pokemon died from "Struggle" after running out of PP.

This also happened with Nurse Joys Eggsecutor and softboiled + substitute.