How to find rude blade?

[Single celled organism]

idk it's in carssa keep or whatever but i don't know ho to get their

[Brynn]

chests in the cresent keep usually drop em, might need to redo room fights a bit, but they dropped fairly often for me.

[Wolfle_Kat]

Mouths sometimes drop them too, also found in Crescent Keep.

[fwops]

I found a couple in the place where the golem and poison slimes are, the room that sends out magic boars for the last wave gave me two I think

[WonderSparks]

As for actually reaching Crescent Keep, you have to go past the first dungeon to the Effold Terrace, hang a right to another portal leading to a linear connecting path (whose name I forget, but it has a lot of tree stump-looking enemies called Blightwood) and then that portal leads to the Keep, where there's a fast travel point to the right of the entrance.