Fiddle of gold against your soul

[NecroDancer]

I'm currently playing a level 5 teifling warlock (feind, pact of time) in a curse of strahd campaign. I'm thinking of multiclassing into a bard, the fluff being that he's going to be a herald to his demon lord graz'zt, I am wondering how many levels of bard should I take and what spells should I get. My current spells are suggestion, scorching ray, invisiblity, hex, fly, and fireball. My parties composition is a devotion paladin, a WotOH monk, an arcane trickster, and a Drow light cleric (who doesn't do much healing).

[Degwerks]

I'm unsure how far the leveling goes with that adventure, but I wouldn't go less than 3 levels of Lore Bard. You could even continue on in bard and you'd still be a solid character.

I'm playing a very similar warlock (11th lvl) in Rise of Tiamat. I have the option of retraining some of my warlock levels into Lore Bard. I can't decide on 3, 6, or 8 levels of bard...

[Belac93]

It goes to level 10. I would suggest 4 levels of bard, and 1 more level of warlock. Then you have your 6th level warlock ability, and you will get an ASI from bard.

[MrStabby]

I would suggest 1 level of bard.

With this you can extend your spell selection with some spells you otherwise couldn't get:
Faerie Fire, Tashas Hideous Laughter, Healing word and featherfall all spring to mind. This also gets you 2 extra level 1 spell slots per day to use for these support actions.

You can also get Bane without the invocation.

Your extra spell slots can also be used for Warlock spells. Maybe you want to use concentration spells in more encounters - so hex from a level 1 slot for those easier encounters might be a good deal, as an example.