the deeply unsatisfying thing about Jonah's arc is that he, out of all characters, gets relegated to the position of plot device. his agency in causing the apocalypse is completely ignored in favour of feeding into Jon's guilt and sense of responsibility; and since we, the audience, and even the characters themselves, know that it was Jonah who ultimately planned the Ritual, it comes off as rather forced. heaping the blame onto Jon is not only an unfairness to him, but to Jonah himself — the narrative in season 5 utterly fails to acknowledge that Jonah Magnus has been the driving force behind the development of the main character and of the very plot of the show. the Web may have been setting the orchestra in place, but Jonah was very much the conductor.

what little insight we gain into who Jonah was as a person is conveyed through other characters' perceptions of him — which would be interesting on a metatextual level if it had been intentional, in which case I believe the creators would have at the very least given us the protagonist's perspective on the man who shaped him. instead, Jon in season 5 seems remarkably indifferent to Jonah, and seems content to take full responsibility for the fate of the world; which, again, might have been an interesting thing to explore as a character trait, and not as a narrative truth. but I digress.

Jonah himself is a man who is fundamentally so afraid, so utterly terrified of becoming a victim he sacrifices the entire world for a chance at keeping himself safe from fear. he knows someone is bound to figure out the truth of the Rituals and eventually perform a successful one, and he wants, nay, needs to make sure he gets there first. we see him sacrifice every single one of his human connections over several lifetimes for the sake of achieving his goal (it's no coincidence that the non-Eye avatars with closest relations to the Institute are the Lukases; Jonah's terror of powerlessness has led him to viewing every one of his friends and colleagues as sacrificial pawns. it's an awfully Lonely place to be). he knows the world is hurtling towards a balance of stark duality, and seeks to place himself above it. there is so much about him that could have been elaborated on in ways that would have advanced the story.

but even if you don't particularly care for Jonah as a character (to each their own, I suppose), there is no denying his importance to the character of Jon. he made the protagonist. it's unthinkable that Jon would have no feelings towards Jonah other than a vendetta that, even with all the stakes laid out, still comes across as superficial. yet throughout all of s5, there is little to no emotional engagement with the character of Jonah on Jon's part. even Helen is afforded more emotional significance than Jonah, which makes no sense at all.