Where to find Edmond's Sword?
Is it in the orcs cave if so where is it? I'm currently where the Last King of Throns is

It seems pretty impossible to miss it to me, the enemy who has it is in the way to the Orc King.

Yes, at the lowest level of the orc caves. Around one or two rooms before you face the orc khan, a fake Edmond will approach and initiate a short dialogue before attacking you. When you defeat it, the sword should drop on the ground. Hold the Alt key if you have difficulty locating it among all the loot dropped on the ground.