Two truths and a lie...

[Tar-Verimuchli]

Originally Posted by Tar-Jêx

Ibun died in the Sack of Amon Rudh, leading the reader to believe that he was killed their. His fate was vague, and it's probably different through all of the versions.

The Silmarillion just says that Ibun and Mim are captured by orcs while looking for roots away from Amon Rudh then doesn't mention Ibun again apart from Mim's statement to Hurin when they meet in Nargothrond that he is the last of his people. In The Children of Hurin, Mim and Ibun deliberately betray the outlaws to the orcs who insist on holding Ibun hostage and are said to have no intention of keeping their side of the bargain. Mim then tries to kill Beleg at Amon Rudh but Ibun is not mentioned. The Unfinished Tales skips the events at Amon Rudh. It's reasonable to conclude from the Silmarillion and the Children of Hurin that the orcs hold Ibun hostage away from Amon Rudh to make sure that Mim keeps to his side of the bargain then kill him after the sack.