So by Act 2 we've determined that a) the gods are probably doing something rather bad by taking people's Source from their souls and b) that the gods are Eternals, . This would have neatly set up a final act where we challenge the gods for divinity and then choose whether to rule or set up a new order or whatever. Except that this plot has more moving parts than that, and Dallis, who I think we're supposed to assume is working for the source king or the void but actually isn't, purges the huge source wellspring at the end of Act 3, at which point your gods attack you and you just... kill them, basically. Which frankly was a waste of an A-list villain group setup for a B-list slot, and also means that objectively speaking there are regular nameless guards running around Arx who are definitely capable of hacking gods to pieces (sure, the gods are weakened by this point, but even so).
So then we all head out to Arx to work out what Dallis did after she stole all the god-level magic, and this was where the wheels started coming off a bit. The early bits were OK, if getting further convoluted as the Magisters (the bad guys who do a lot of trying to kill and brutally torture source users to destroy their source) are being purged by the Paladins, who are alright, but then it turns out the Paladin leader is working for the God King, who is not to be confused with the Source King because the Source King Braccus Rex is a malevolent figure from within recorded history who has a habit of sparking weird cults around him and has a lot of undeath related abilities and the God King is a malevolent Eternal who was overthrown by the first gods who has a habit of sparking weird cults around him and has a lot of undeath related abilities and the Source King is secretly alive and working for the God King but is shackled by Dallis but turns out not to be. Hope you got all that, there'll be a test at the end.
I didn't have the Red Prince, and consequently a whole section of late game Lizard folk content was there but made absolutely zero sense and I had no sensible way to engage with it, once I'd worked out the mirrors fight I hauled myself into the next room, ended up being attacked by the dreamers which got me locked in to being attacked by the next lady who I'd never met before in my life, and once she flattened me once (because I'd run out of resurrection scrolls and was soloing it) I just decided to sneak past her because I had no reason to engage, it was all just very strange.
I was as mentioned playing as Beast, whose Act 4 stuff still made no sense at all. It's abundantly unclear why Justinia is trying to gas everyone in Arx with a doomsday weapon, there's no particular sense that the magisters and paladins are posing an active threat to her and her reign: "Isbeil persuaded her" is part of an answer but that's a how, not an underlying reason. Also, just as annoyingly, the options for confronting Justinia are incredibly unsatisfying, it's basically "shank her in a sewer" or "become the ally of the red handed tyrant" or "piss off and let the red handed tyrant do her own thing". Given Marcus' start is as a possibly jaded former revolutionary it's immensely weird that there aren't any options to try to tell her to stand down & be deposed, or similar (and she might then attack you but then it's on her). It's just this sort of weird "hey, while you're in Arx, someone's threatening it with a doomsday device so just pop over and sort that sometime while you're in town if you could?"
At last we reach endgame. I'm on track and have finally found the tomb of the divine, the game is building towards its grand reveal, and what the game decides to throw at me is first a C-list fight with some guy who I triggered a quest about without actually noticing I'd done so as I was running around a sewer and who turns out not to be a small child but actually to be evil, so that was a thing. Then, uh, there were the immortal magic draining puppets. The prospect of being beaten up by annoying squeaky voiced puppets who can't die definitely does not wildly undercut the moment (whilst DOS1's ending is a bunch more elongated than it should be, it does nail the sense of over-the-top acceleration up to the final fight).
And then we have THE REVEAL as we find out that Lucian the previous divine is not dead, leading to interesting questions like "so how is he still a full Divine but also there was enough source left in the fountain to make another Divine in theory", and "how does any of this make sense" (see next para), and "what the hell, dude". Also Dallis is Fane's daughter and blames Fane for everything. Then Braccus, the Source King, who was an Act 1 boss in DOS1 and is now suddenly the Big Bad after tootling around under a pseudonym in a hood all game, suddenly calls on the God King, and half the bloody B-list villains turn up again, being spat out by the Kraken, which is also back for Reasons. Despite the God King being from and bound to the void, all the enemies here are undead so we don't even get the voidwoken's distinctive look and feel. The final fight as a whole also felt really ignominious, in that I just sat there fending off the B-listers while Lucian chopped Braccus to pieces bouncing around the map and all but one of my guys did not have the movement abilities to follow them up effectively.
Besides these issues, there's the logic, and I can accept a lot of handwaving in games but because I'd been taken out of the reverie anyway I started poking it and it really doesn't hold well. The ending lacks any actual theory of how source works so it's abundantly unclear why they need to source-out you specifically. Like, my guys have 3 source points each - there's at least that much source in the previous room's puppets, or I can just take a trip to the infinite fountain that's sitting in a guy's doom cellar down the road. Also unclear why the world needs to be *totally* purged given the strong implications that before the veil was drained, eternals were already using source, it's just that the veil was a huge source of source that allowed the seven to take power and reshape the world. Nor is it the case that they specifically need us to drain the stolen source from the veil because there's still a bunch of gods out there who are quite specifically not taken out of the picture in Act 3 (D:OS3 should just be Xantezza messing with everyone honestly).
The character work broke down badly at the end for one of my companions too, in the form of Ifan, whose Act 4 stuff might have been bugged, I don't know, but he just randomly decided to off me at the end having been totally supportive for the whole game, supported me wholeheartedly in Act 3, and not expressed any issues. Indeed more weirdly he decided to poot his lil crossbow bolts at me to avoid anyone becoming divine, a thing that I was *explicitly not about to do and then went and did not do*. This was one of the weirdest character breaks I've had in an RPG in a while, it just felt bizarre. Doubly so because him versus me, Lohse, and Fane was stupidly obviously unwinnable, I felt really bad for him.
Conversely Lohse's Act 4 stuff was mostly pretty cool, except needing to reload because the dialogue needed to stop her doing candle doom is very much not clear (in that you can do dialogue that looks very pointed at that but it doesn't do the thing you'd expect). The drama leak basically took repeated hit and runs (send 3 party members in, with Lohse left outside, flatten a few goons, depart the mortal coil, Lohse picks up the remains and teleports to rez, once the goons are all down after a few repeats them go for him directly). My other problem with it was not getting any ending option for staying with her despite the active romance, which felt weird as hell.
No real complaints about Fane, his stuff felt earned, you do you my lil undead buddy.
Once we were past endgame, finally, some of the long set of final slides felt a bit weird. We don't get a chance to object to Lucian remaining Divine-in-name if we purge (which seems weird), you get to offer Han a job and that's not reflected in the slides immediately afterwards, various other things that just sat oddly. You get to learn what happened to a random fisherman from Act 2 who you retrieve a wedding ring for, but almost none of the other minor questgiver characters (like the little girl who had an undead cat called Buttons who was much more memorable than Wedding Ring Guy).