Originally posted by avatar.zero:

Flametal and its ore is available in vanilla, but the Dyrnwyn is not (or, at least, not by normal means - it can only be created by activating devcommands and using the spawn command from the console). It's like the "Killsaber" from Knights of the Old Republic II - a "cheat" weapon in alpha that still exists in the game files, but is technically disabled and therefore not available through any normal means, not even the recipe.

Do you know if Valheim Plus add those weapons to be crafted? I'm not sure, but it my friend is hosting the dedicated server, and he told he's using only Valheim Plus... At some point he opened the Valheim files and saw a Stone Pickaxe there, and I think he added to the game... It seems he added more than just the Stone Pickaxe.