Is there a way to delete vanilla items/blocks?

[shut arch]

Probably mixin to where they're registered, but you'll quickly run into pain once generation and loot tables and even air being gone causes you pain

[nimble marlin]

ok ill try

[undone quail]

Did you manage to do it?

[slow gulch]

why do you want to do that

every mod using the item you've deleted anywhere will crash at some point