Wow, thank you very much for the info, that's great. I especially wondered about the passive damage. I don't use Illithid abilities, so that's a problem which would remove one of the most attractive features of the build.
I could not withstand and again made me a similar build as your's yesterday. It would solve several "problems", f.e. apart from that I like the idea of a sworddancer very much, I could wear the fancy Mindflayer outfit from Basket Full of Equipment mod with more credibility than on my Sorceress, and my group would be more balanced, with me as melee it would be easier to use both Gale and Shadowheart in addition to Astarion or Karlach. Three casters is a bit dangerous sometimes.
Yesterday I faced Sarevok first time in the game and the build showed some weaknesses. I could not cast Haste several times because of Counterspell. The one time I succeeded I lost concentration 5 seconds later because I had to run about an electrified surface (we needed a lot of magical damage because the guy was nearly not hittable with physical damage, and my group is specified for lightning, so such surfaces weren't avoidable). I could wear the ring which makes you immune to get shocked, but I like other rings more. Let's see.
I don't like Haste anyway, a totally op spell, I almost never used it. It's better in Honour mode but still bad, with the second cast action it offers. How important is Haste for your build and what are your experiences in difficult combat? I think the concept does not need Haste, so I also could remove Wizard from the classes.
The second problem was the low hit chances. The build (Bard 8, Cleric 1, Wizard 1, Paladin 2) has no abilities to improve hit chances other than first hit the enemy (except undead) with something (unlike a Fighter/Battlemaster f.e.), or do I overlook something? Isn't that a problem against boss or semi-boss enemies (other enemies don't count for me)? I'm of the impression that you soloed such bosses? Does the most damage in such cases come from misses and Stage Fright?
Last question: How do you get to 22 Dexterity? I have 22 Charisma as Sorceress because of one item but I don't know a similar +2 item for Dexterity.