Eye of the North is more of a sequel to Prophecies than any other campaign, and coming from Nightfall, running Prophecies explains a lot of things that are taken for granted. For example, there is a quest in the Asura lands involving the White Mantle. I completed it with no idea who these people were or why they hated us so much. There are clans of dwarves, and I am for unexplained reasons allied with the first ones and fighting the latter to the death, although that’s normal with dwarf clans. There is Gwen, who I recognized from having tried pre-Searing Ascalon years ago on a friend’s account but who loses some of her impact if you never saw her there.
Because of the semi-random order in which I have seen Prophecies, I am sure that I am missing part of the story, but it seems like there was a big switch between Acts I and II. We open with charr and bandits, then the Searing, then the charr drive you out of old Ascalon, then the charr completely disappear for at least 60% of the story. Joining Prophecies as a character from another campaign, there are no charr around at all unless you revisit the early missions. Nothing. It is all about the White Mantle and the secret masters behind them. Unless you started with Prophecies, you could plausibly beat all three campaigns and never meet the charr outside the Ebon Vanguard arc.
I am reminded at this point of Asheron’s Call. The big cataclysm there involved the olthoi who were then absent for most of the game. There is something to be said for keeping the big villains as the big villains, rather than having them level up along with the hero, but it was a great shift when an update flipped the endgame to being olthoi, olthoi everywhere. Oh yeah, this is what Asheron called us to deal with. (I imagine the story has moved on.)
The entire opening of Eye of the North seemed rather confusing, at least at the point I reached it. Destroyers are trying to destroy the world, or something, and these dwarves have for whatever reason enlisted me, as the nearest person?, to help them. And then there is this other short dude, from a race that I have not found outside EotN but who seems familiar to everyone else. And then the Ebon Vanguard appears, and the charr are villains again. The norn seem explicitly new, so that’s comforting.
Another moment of crossed threads comes near the end of Nightfall. The end bosses of Prophecies and Factions appear as minions of the Abaddon. I had met the boss of Factions, but not Prophecies, so I did not know this was a subjugated archvillain. Reaching the end of Prophecies made Nightfall make more sense, except in the sense that I destroyed the departed spirits of my enemy in Nightfall before they perished in the earlier campaigns.
Maybe it was a mistake to avoid the wiki and go into the storyline unspoiled. Much like the gameplay, the story seems to be assuming you have the wiki or already know everything. Since my Nightfall character apparently met Mhenlo … sometime, maybe he also already has the in-character knowledge of what is going on that I could acquire outside the game.