I'm playing as Ifan (Summoner/Ranger) and Fane (Fighter/Tank), my mate's playing Sebille (Rogue/Necro) and Lohse (Enchanter). I've actually started soloing it with that set up too, from the point we were at in co-op last weekend. Long story, but my mate's not very good at the game, doesn't want to put the time in to understand the skills and systems. Part of the reason we dropped it for a few months was because we were getting bogged down and it was getting frustrating not to make any progress. I'm happy to let him get on with it without interfering but wanted to move the game on for myself as well, so I picked up our latest save and completely re-specced the characters so I could solo. We've carried on with the original set up in our co-op game, apart from me re-speccing Fane into a tank, and giving Ifan some ranger skills.
My other solo games I played as Lohse and The Red Prince.
Giving a lot of thought to getting the game on Switch so I'm not tied to the pc to play it. I've put 140 hours into it so far, one way or another, on Steam. Being able to carry saves from Steam to Switch and vice versa is very tempting.