I've been blessed not to run into players like that yet. Though I've stuck with the B/X and it's retro-clones so far. I don't know if homebrew or other alternative systems attract more people like that or just they expect everything is on the table now if it's hombrew or such.
What kind of setting or theme was it and what system are you using if you don't mind me asking as I could see a way for them to work depending on it.
It's my own personal rpg I whipped up for OSR-y games with a degree of character creation. It's ACKS + DCC + a lot of obsession around the idea that Gary Gygax threw in in the LBBS that you could literally just play anything as long as it was sufficiently weak at the start.
The character creation is basically pick a race (race has little to no effect on anything) and a class. There's three kinds of ability dice (trick for skills, warrior for fighters and drain for healers) and then you bolt on 4 specific features. The game in its current state has 14 features for trick dice, seven for drain dice, and five for warrior dice, alongside 56 other general features for a total of 82 features. Like I'm very open for letting people choose their features if they don't want to use one of the pre-made classes. Warriors, for example, start with technically 4 attacks, with the
Companions that gives them 3 best friends/bros that will fight with them and follow commands (they will not, under any circumstance throw their own lives away and require a lavish burial on death or the feature ceases to work with your living companions abandoning you and and you cant get more). You can be a lich, a witch, a druid, all kinds of wacky bards and such. Spellcasting is not something you can just "be". Let me post the "lich" page to show you.
I just can't do shit like a brain parasite that remains effectively immortal in this system. Nor can I figure out how the fuck you're gonna be able to do shit like pokemon trainer, even if the companions.
This player is pretty aggressively bad faith though, I might just boot him since he threw his dice across the room because he got in trouble with the law after making a habit of killing and eating people for rations in a dungeon.
Edit: To answer before asked, you scale off HD because you can get more HD than you can levels. Levels only really determine the power of your ability dice, while HD determine the power of your features. Also, you can obviously do more than what you're given here. These are just your four innate features. If you want magic, you have to quest for it, if you want to fly, you have to quest for it, your combat ability etc all of this is determined by questing for it. Players generally like it, one of my players likes using the Lich's paralyzing touch with its drain attacks to do stealthy shit. Uses the shades to scout, etc. Pretty good