u/khangkhanh

Right after the first mistle of the cave. There are a lot of enemies and you can even farm D rank code there very quickly with AOE spell from lvl 1 like falling sun or halberd spin to win.

They die and drop their weapon often too with help alots with the friendship.

Just jump down use the spin to win or falling sun and kill the nearest group then use it again to kill the group near the pathos and then reset.