In fact, I am deeply convinced that the most probable candidate is Guigues IV, Count of Forez (Comte de Forez):

*(depending on the authors, there are two numbering schemes for Guigues counts - we are interested in the one that died in 1240/1241 who had two sons - the next Guigues and Renaud - he might be either IV or V)*

* His name is a perfect match, pronounced [kɔ̃t-də-fɔʁɛ] is as close as you can get to kondofrei
* He left for Jerusalem with the Baron's Crusade in 1239. Then at some point, a group of knights were called by Pope Gregory to defend the new Latin Empire and headed for Constantinople. I can't confirm that Guigues IV was one of them. They marched through the Latin Empire, without fighting, and reached the Bulgarian border. They were able to negotiate an agreement with Ivan Asen II of Bulgaria to let them pass on their way back
* The group that headed to Constantinople was led by Baldwin II, also known as Baldwin of Courtenay, the last Latin Emperor
* The official death record of Guigues IV is from 29 October 1241, but "Histoire des Ducs de Bourgogne" says that his death certificate and testament were in fact written by his son after it became clear that he had died during the Crusade on his way back - his death is first mentioned as early as February 1241 - and his son did not receive his title until 1242 exactly because the circumstances surrounding his death were not clear
* He died from illness, which is consistent with the local legend
* His son, Guigues V, travelled to the East to bring his sarcophagus - this part is not very clear since he also took part in another later Crusade