Character Optimization Help

[TheBrassDuke]

This is my current main, Carabosse.

Shadar-Kai* Aberrant Blade-Sorlock 16
(Warlock Hexblade, PoB 13/Sorcerer, Aberrant 3)

https://www.dndbeyond.com/sheet-pdfs/caineporter_37326068.pdf**

We’re coming close to the end of our campaign now, almost into our second year of irl play. We have a super BBEG inbound, and I don’t feel nearly prepared.

I’m not an optimizer, and so may be missing out on something with this character, something that could help me improve, and keep my friends alive. I’m not sure why it’s been stressing me out so much, but it’s come to this point.

Playground, could you take a look and help me optimize my next three levels please? Thank you all in advance.

DM classified my type as Fey (Dream) in this campaign.
I have a few custom-named items, and some actual custom pieces of equipment. I will individually post for each of them upon request.

For instance, the Robes of the Archfey are actually Archmage Robes, and so on.

[Specter]

Don't have the time to read through it all, but looking only at spell selection: if you're focused on melee, you should definitely want some buffs in there, like Spirit Shroud.
If you imagine mooks will be involved, I'd prepare Synaptic Static. If you can reliably affect the BBEG saves, then Banishment or Hold Monster go up in value.