If it helps, historically Myrddin Wyllt [Who later became mythologized as Merlin] went insane after watching the last of a King Arthruis' grandchildren and grandnephews kill each other in a massive battle. He ran screaming into the woods where he spouted insane, prophetic poetry which was later written down by the bard Taliesin and supposedly died a triple death. He was chased off a cliff, hung in a tree, and drowned. Or was chased off a cliff, impaled on a stake, and drowned. Depends on who you ask. Still, not a nice way to go. Would that be enough to take out Gilgamesh the King, immortal human, Ancient of Days and First of the First People? Probably not. He figured it would take a nuke to take him out remember?