Some curiosities abt Shiny Gengar: Shiny Gengar isn't bad,the original just got worse,in FireRed&LeafGreen,you could tell them apart easily,the purple just got closer to the blue of the shiny Shiny Gengar is confermed as blue
Ohhh i did something kinda similar, instead of den's i used the static wild tera-mon encounters, im limited to catching thoses plus when certain story beats are met, im allowed to sub in with a few random terra den raid mons also, just to keep it fresh, and also as a saftey net incase i lose any pokemon, (for reference: there are 3-4 static wild tera pokemon of each tera type on the paldea map) depending on the type, if you get lots of deaths you may not have access to certain pokemon types which, would really suck. But the random mons can sometimes end up being really bad depending on circumstances. You've only got so many times you're allowed to catch tera den mons, i kept them limited, so you'd be forced to use the static mons. (No using the starter as its not apart of the allowed mons, instead my technically a starter ends up being a Water Tera Jigglypuff (its the lowest level static encounter)) Kitagami and The Terrarium have static terra's too, they'll be included in my challenge also, as part of the post game. Also NO changing the tera types on the preset pokemon. Work with what you've got. Thankfully these static encounters usually have moves of these odd typings in their moveset, and usually they come with a move already of that type. So this run ends up being pretty fun. I also made it a (soft) rule, a preference of a sort, essentially, they must possess one move, that hits for the same type as their tera type, if not, the pokemon must possess Tera Blast, you can still use it in the beginning when you dont got many mons, but late game the rule is more enforced. Paldea interactive map is very useful for this challenge. Though i might do a den only run soon, looks fun. Very very random.