Finally got through the game with my Azata character (which was a Core Ironman run for the related achievement) and Trickster/Swarm/Legend character, which just leaves Demon as the last mythic path I have to take. Azata wasn’t very good, though it at least had a unique ending. Trickster turned out insanely good in basically all respects, while Swarm would absolutely be a challenge run if you don’t happen to have the Midnight Isles DLC installed. As for Legend… it’s pretty damn powerful when used with a fighter build and adds some interesting exposition regarding your soul.
Before starting my final main campaign playthrough though I thought I may as well run through the Inevitable Excess DLC (with Legend) for the import bonuses, but since I really didn’t want to play it all that much I did so almost entirely on Story difficulty. Switched to Unfair for Inevitable Darkness and managed to kill him on the second try with the combo of Guarded Hearth, Freebooter’s Bond, Smite, Fortune Hex, and then just wailing away with Dimension Strike.
Overall I’d have to say the DLC is just as bad as suspected, with it being essentially half pointless/tedious combat and half infuriating platform puzzler. I’d strongly suggest skipping it unless you really need the import bonuses for something like a Test of the Starstone run. Something I’m currently waffling on whether to attempt or not… although I suppose I could simply start out on Unfair and just lower it if it ever become too much hassle.