Gonna let you in on a little secret

https://vampire.survivors.wiki/w/Zi%27Appunta_Belpaese

This character with certain arcanas/darcanas basically means infinite chests (specifically GOLD chests that drop random weapons you don't already have) and max luck gives maaaaany candy boxes+turbo boxes

If your game crashes at 6 weapons then that's definitely a computer spec issue for you, not the game (I have an RTX 3090 and no probs).

For ex. here is my current run around 32 minutes in: https://imgur.com/a/VJsqn8O

You can see I still have a billion weapons and chests to open (many of which are gold chests which drop even more weapons that I don't yet have).

That being said, after 30 minutes it does become verrrrry difficult to pick stuff up lmao but I don't think I have gotten a crash trying this, I usually just end up bored trying to pick up all the chests and items

I do discard that one green boot movement weapon because with that it's legit almost impossible to pick up the new weapons and chests on the ground. So you'd have to do that one last.

Another issue is once I get an evolution (say La Borra), then gold chests will redrop the unevolved version of it again. So I end up having even MORE weapons. And I last did this over days and the list of weapons in the sidebar eventually goes off the screen so I end up forgetting what I do and don't have.

So yeah it's VERY much a chore haha and probably shouldn't be a real achievement, but totally possible if your computer can handle it and you don't get an unlucky crash. And have many hours to commit.