Before taking a break from bg3 I created a build for my second playthrough (which is postponed for a Definite Edition or some major overhaul.) Now that I'm satisfied with it I might as well share it here. Still not very familiar with DND5, so I hope it makes sense.
A crowd controlling artist and a convincing party face. A spell focused Bard as a good or neutral enchanter in contrast to a Succubus.
For style reasons and for Spell DC increase (which we absolutely need for the build) we want a robe. But to keep up concentration we need high AC and ideally Constitution Saving Throw Proficiency as well (Sanctuary from Magical Secrets could work as alternative, but it's boring being idle / unable to attack while the crowd is confused / hypnotized and Cutting Word will end the condition anyway.)
With Shield Proficiency from Half-Elf, Draconic Resilience (same as Mage Armor) and Constitution Throw Proficiency from Sorcerer we get all that while staying a full caster.
Feat Actor gives Expertise in Performance and Deception even without prior Proficiency, so we have room for even more Skill Proficiencies. And it raises CHA +1 to 18. Perfect Feat for this build.
For crowd control and enchantment spells it's pretty useful to act before the enemy can, so we increase the Initiative +5 by picking the Alert Feat.
Race: Male or female Drow Half-Elf (Fairy Fire, Darkvision, Fey Ancestry and Shield Proficiency). Background: not sure, probably Urchin or Entertainer Stats: 8 STR, 14 DEX, 14 CON, 10 INT, 12 WIS, 17 CHA Classes: Sorcerer 1 / Bard 11
Sorcerer 1 (Brass Dragon Ancestor) Proficiency: Constitution Saving Throws, Intimidation, Persuation Passives: Mage Armor (permanent), Fire Resistance 4 cantrips: Friends, Blade Ward, Fire Bolt, Minor Illusion 3 spells: Shield (reaction), Magic Missile and Sleep (from Dragon Ancestor)
Bard 2 Class Action: Song of Rest Spell: Animal Friendship
Bard 3 Subclass: College of Lore (Cutting Words) Expertise: Intimidation, Persuation Spell: Blindness Proficiency: Acrobatics, Stealth, Perception,
Bard 4 Cantrip: Dancing Lights Spell: Hold Person Feat: Actor
Bard 5 Spell: Hypnotic Pattern
Bard 6 Class Action: Countercharm Spell: Fear Secrets: Counterspell (Reaction), Daylight (useful in the Shadow Cursed Lands)
Bard 7 Spell: Confusion
Bard 8 Spell: Polymorph Feat: Alert
Bard 9 Spell: Hold Monster
Bard 10 Cantrip: Mage Hand Spell: Dominate Person Secrets: Dominate Beast, Slow Expertise: Perception, Insight or other Skills from Background Proficiency
Bard 11 Spell: Otto's Irresistable Dance
Gear and Conditions
Early on any shield plus Warding Bond, Bless and Aid from your Party Cleric. Pick up any gear that pushes Spell Save DC (Robe, Quarterstaff, Headwear). Set Cutting Word, Shield and Counterspell reactions on "ask" to not waste Spell Slots / Bardic Inspiration when the reaction isn't needed.
Later in Act 2 buy the Cloak of Protection (AC +1, Saving Throws +1) and take Ketheric's Shield (AC +2, Spell DC +1). In Act 3 buy the head gear Birthright (CHA +2) and consider looking into a certain Mirror for another CHA +2 (CHA 22 in total). Finally take the Gauntlet of the Tyrant for another +1 to Spell DC.
Hope the build makes sense and isn't too obvious.
At Level 12 with AC 19, +8 to Constitution Saves, +14 to Deception/Intimidation/Performance/Persuation and a Spell DC of 22 nothing will resist (should work at lower levels too, but didn't test yet.)
After finishing the build with a Lyre as instrument I couldn't help but think of PJ Harvey. And if you believe no way she is ever able to hypnotise bosses, you'd be wrong :P