Famed and Legendary Weapons No Luck

[Tiberius Fireskull]

Don't look for them. It sounds silly, but it works for me. I go to loot in the treasure room for fun with a friend, not looking for anything. First loot skull chest that drops gives me a famed dagger. It was unfortunately lost in a reset, but that's not the point. Just loot for a while, and don't try to find anything. Eventually you'll find something.