I think there’s quite a bit of parallel between Agnes Montague’s death and Jonathan Sims’s death in episode 200. Let me explain what I mean by comparing the lines about Agnes’s death to what happens to Jon:
“But if she ceased, not in cumulation of fire, but a cold and quiet death” - Jon did not go out in a spectacular fashion like you would assume the man who started the apocalypse would. He was not looked upon by The Eye, he was not drained of his power until there was nothing left, he was not consumed by fire, or rot, or darkness. He was simply stabbed. He taken down by the same thing that would that would take down any human.
“Perhaps her spark would return to the Lightless Flame and she could try again” - Before Martin stabs him, Jon mentions that maybe they’ll go “somewhere else” where everything will work out. Then they’re presumably “returned” to The Eye as they are sucked up with the fears and (likely) sent away with them.
“So we hanged her, as she requested” - Martin stabbed Jon, as he requested.
“All because of that most insidious of emotion, hope” - When Martin asks Jon if he’s sure about sending them all away, Jon says, “No. But I love you.” Despite the struggle Jon has with his humanity all through out the seasons, he spends his last moments clinging to the hope that maybe, just maybe, he and Martin will get to end up together. In somewhere else where everything works out. It’s easy to argue that his hope is an insidious one when it drives him to sacrifice their lives to release the fears into another world, but it’s a hope, and that’s all that really matters to Jon in the end.
It doesn’t surprise me that there’s such an overlap between the death of Jon and Agnes. They were both avatar’s who were filled with doubt about their role in the world and decided to sacrifice themselves rather than continue down the path assigned to them. They were so, so, alike. I really wish they would have gotten the chance to meet.