Finished with Siugnas, which ended with a three phase boss fight where the second and third phases both gave separate achievements (
Thrill Seeker and The Ultimate).
I ended up not making any party members into Knights. I've heard that something about making people into Knights makes something about Siugnas' last boss easier, but I gave it a blind run in the hope I could get through the run without doing any more party tinkering or upgrading, and it ended up working out. I had
Mido as a longsword/rapier user, and Humans have a longsword skill that hits all enemies that move after him with a chance to Stun (effectively just hitting all enemies most of the time, because he moves early and had a Role to help him go even earlier), and a rapier skill that hits all enemies and undoes all Reserve arts. Between those two skills, it made the accompanying boss support enemies with a high guard rate a lot easier to deal with. If I understand correctly, he woud have lost those as a Knight because those are Human exclulsive, so I'm glad I gave it a blind run before converting everyone into Knights, since those skills carried me through. Plus, now I have more materials in reserve for whatever comes next.
I'm playing scenarios from the ones I'm least interested into to the ones I'm most interested in, but I ended up really liking Siugnas' scenario. He seems to get a lot of unique events because of his role as a Dark Lord, and the focus on exploring the worlds his initial party members are from adds even more, creating something resembling the companion system in Scarlet Grace, which was an element that was missing a bit for me during Mido's run. I also liked that the tone was more Adams Family for readers of Boys Love comics than actually edgy. It's comedy dark, not actual dark.
I feel like I have a grasp on how magic works now, and by the end of the run Philospher was a pretty effective mage. It definitely feels toned down a bit from Scarlet Grace, but I think the flilpside of that is that it's now possible to be a good mage and a good melee character. Also, if you have strong spells in your skill list, there's a chance of using them during an overdrive, so you can end up firing off a spell that normally requires two turns of charge time for a low BP cost with 0 charge time. There's a luck element to that so it's not very reliable, but when it happens it's very satisfying.
In Siugnas' final area, there was a hilarious fight that kept scaling to ridiculous levels every time you won, to the extent that the time I lost that enemy was doing damage in the multiple 1000s. Maybe it's theoretically winnable if you've done countless loops and have the best of everything with some very tweaked build to reliably Stun or Paralyze, but I thought it was a funny way to do a "you're not actually meant to win" style encounter.
I was a bit unsure which of the next three to start next, but I think I'm going with Ameya since it sounds like even more than the others she's built around doing multiple loops before it opens up, so I want to get at loop in rather than putting her off.
Also, FYI, there is at least some support for this game planned, because Kawazu is very active on Twitter taking bug reports and talking about some UI changes planned for the next update, like having some visual indicator of what equipment you currently have materials to upgrade.