In the graphic novel, Trollhunters: Tales of Arcadia--The Felled, Deya went to find Merlin to get him to tell her what her destiny is, but Merlin wouldn't tell her so she touched an omniscienstone and saw future events such as the creation of the amulet, Jim battling Gumm-Gumms, Blinky's death, Jim as a half-troll hybrid, Draal as the Trollhunter and finally human bones of a Trollhunter. A few of these events will never come to pass becouse Draal is dead and he was in the panel where Blinky's dead body was shown. Draal died and he was never a Trollhunter--except for that episode where Merlin sent Jim back in time and Jim never became the Trollhunter which makes sense with the panel speech bubble text "Events that would--or should not--occur". The Last panel is what concerns me, those are clearly human bones in the Trolhunter armor. Here are the following possible scenarios.
1)Jim turns back into a human and he dies the next apocalyptic event, the bones aren't of a Troll becouse there are no horns.
2) Troll Jim dies and a new human Trollhunter is chosen and they die during the next apocalyptic event
3)This panel is of a different timeline where Jim never became a Troll and he died, but that doesn't work either becouse Trolls don't have bones.
4) This is one possible ending to Jim's story.
***This is all assuming this comic book is canon, it is written by Guillermo del Toro which in my head means it becomes automatic canon.