It's on the Warlock's Archfey Expanded list. So, three times per short rest at level 7.
Warlock is perfect thanks.
I forgot to check their sub-classes.
Though it's 2x per short rest. I need warlock 11 for 3x.
Depending on party makeup, they'll be able to cast it more than any other will.
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.
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.
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.
Going further in rogue will boost damage with sneak attack. 4d8+4d6+dex+cha is a lot of damage to deal to someone who moves. Plus they get a bonus ASI at 6. Not sure what sub-class though.
Also, bladesinger needs Int, and i'll already need Cha/Dex + warcaster.
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
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.
Fighter 3/4 i could see. Action surge is always good, and can let me "quicken" greater invisibility, and battlemaster's precision strike helps ensure i hit.
Goading attack to just to be mean. (disadvantage to attack anyone but the invisible hidden guy!!!).
So maybe warlock 8/fighter 4/rogue 8?
Though rogue 10 is tempting to boost my stealth.
And warlock 11 is also tempting for more invisibility...
Hmm...