Warlock is perfect thanks.It's on the Warlock's Archfey Expanded list. So, three times per short rest at level 7.
Well this will require some party cooperation. I need enemies to move to get an OA for booming blade to trigger. And they won't if my party rushes them.Depending on party makeup, they'll be able to cast it more than any other will.
Flying (winged tielfing or the birdman), let's me hide not just next to someone, but above their head too. Much less chance i'll accidentally be hit by a breath weapon or something.Cunning action is a 2 level dip into Rogue. After that, I'd consider Wizard for Bladesinger for the concentration boost (AC and CON saves) that Bladesong provides and some spell slots for other spells. You also get Mage Armor from either Warlock invocation or Wizard spells. You'll have 4 invocations so you've got a pick of others. I'd either go Fighter 1 at first level or Human Variant for CON save proficiency.
I don't see how fighter 11 since i'm depending on booming blade for damage. EK 7 doesn't help either since i need the bonus action for hiding.Warlock sounds solid and so does the fighter starting point for CON saves + weapon / armor. But I personally don't like the idea of going into bladesinger. I would much prefer to continue into fighter to get the extra attacks, feats and features there. Something like Fighter 11 / Warlock 7 / Rogue 2
Blade pact warlock already gets you extra attack via invocation so i think taking fighter past 4 is not as useful.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.