Build advice for heavily home brew modified TWFing Hexblade

[Mongobear]

In a new campaign beginning on New Year's Eve, I will be playing a Shadar-Kai Hexblade. My DM has been working with me on how my Patron formed the pact, and it boils down to I am literally carrying the Patron Sword around with me, but I am way to weak to actually use it, it is simply a plot device.

I want to be different, and am planning to make a TWFing build, with an original plan to dip 2 levels of Fighter at first, then go full Warlock. However, the DM had an idea that since I am literally carrying the patron sword around, I will gain a few additional benefits.

Namely, the fighting style, and whenever I summon my PotB sword, I create an identical weapon in my offhand, however I cannot use this if I find a magic weapon, only the default free blade out of nothingness. Also, as we gain levels, I will gain a similar effect to the +2/+3 Pact Weapon Invocations near their levels from the UA months ago.

So, here is my actual question. What options should I focus on as I level up through Warlock? Would Hex be worth it, despite the competition for Bonus Actions? Darkness/Devil's Sight for advantage shenanigans with Elven Accuracy? Is the Dual Wielder feat worth it for d8 weapons, or are d6 weapons enough? Is dipping fighter for BM maneuvers worth it since I would be a short rest Nova machine? How about spell choices and other invocations aside from the obvious PotB melee striker ones?

[Mongobear]

Any ideas or insights? Kind of surprised it's been all day and nobody has even told me to just play a coffeelock

[LeonBH]

You don't need to go Pact of the Blade anymore. Since you have your hexblade weapon in hand that also conjures an offhand weapon, which also gets +2/+3 bonuses later on, it really becomes senseless to proceed with that Pact.

Take a level in Hexblade to validate your concept. Then take the rest in Rogue for Sneak Attack. Swashbuckler goes great with the Warlock level since its abilities key off CHA. You get two chances to proc SA, and SA triggers even if they're just standing there by themselves.

[Butler2102]

Seems like you already have a good idea of what you want to do and what your DM is giving you to empower your character concept. But I'll add my 2cp where I can.

For spells, I'd still grab EB or Toll the Dead for damaging enemies that are beyond your reach. Hex will be worthwhile if you have one big baddie to whittle down. But you'll also want to put your Hexblade's Curse on that guy, so that'd be two turns of setup before you get to TWF on turn 3. I don't think it's necessary. Grab Armor of Agathys instead. It doesn't require concentration, last an hour, scales really well with those high level Warlock slots, and it rewards you for being in melee like you want to be. Same with Hellish Rebuke (and offers some duality with the cold damage from AoA). Darkness/Devilsight works well enough, but it's generally annoying for your teammates who then cannot target those enemies with the many spells and effects that require you to see your target. If Shadow Blade can be duplicated as well, that should absolutely be a pick! Shadow of Moil has the same pitfalls as D/D listed above, but without the cost of an indication and giving some free Hellish Rebuke type damage.

As for Invocations, Thirsting Blade is a given. Sounds like you've got a good deal with Improved Pact Weapon (if it also includes the XGE goodies, you can make a bow, replacing the need for a damaging cantrip). I think Eldritch Smite is kind of a trap now, since it can only be used with Warlock Slots, unlike Divine Smite which appreciates spell slots from any source. Your slots are limited as a Lock, so I'd recommend using them on something that offers longer effects and returns. Life Drinker is obvious at higher levels, where your TWF will finally shine.

As for feats, you want to max Cha asap. So I'd only take Elven Accuracy if you have an odd Cha mod (meaning you rolled for stats, as the elf subclass you mentioned gets a +1 to Cha, so with Point Buy, you should be starting with 16). After maxing Cha, do whatever suits you. Lucky and Alert are solid picks that are universally helpful.

Hope that helps. Enjoy your Gish!

[Mongobear]

Seems like you already have a good idea of what you want to do and what your DM is giving you to empower your character concept. But I'll add my 2cp where I can.

For spells, I'd still grab EB or Toll the Dead for damaging enemies that are beyond your reach. Hex will be worthwhile if you have one big baddie to whittle down. But you'll also want to put your Hexblade's Curse on that guy, so that'd be two turns of setup before you get to TWF on turn 3. I don't think it's necessary. Grab Armor of Agathys instead. It doesn't require concentration, last an hour, scales really well with those high level Warlock slots, and it rewards you for being in melee like you want to be. Same with Hellish Rebuke (and offers some duality with the cold damage from AoA). Darkness/Devilsight works well enough, but it's generally annoying for your teammates who then cannot target those enemies with the many spells and effects that require you to see your target. If Shadow Blade can be duplicated as well, that should absolutely be a pick! Shadow of Moil has the same pitfalls as D/D listed above, but without the cost of an indication and giving some free Hellish Rebuke type damage.

As for Invocations, Thirsting Blade is a given. Sounds like you've got a good deal with Improved Pact Weapon (if it also includes the XGE goodies, you can make a bow, replacing the need for a damaging cantrip). I think Eldritch Smite is kind of a trap now, since it can only be used with Warlock Slots, unlike Divine Smite which appreciates spell slots from any source. Your slots are limited as a Lock, so I'd recommend using them on something that offers longer effects and returns. Life Drinker is obvious at higher levels, where your TWF will finally shine.

As for feats, you want to max Cha asap. So I'd only take Elven Accuracy if you have an odd Cha mod (meaning you rolled for stats, as the elf subclass you mentioned gets a +1 to Cha, so with Point Buy, you should be starting with 16). After maxing Cha, do whatever suits you. Lucky and Alert are solid picks that are universally helpful.

Hope that helps. Enjoy your Gish!

The competition of hex and hexblades curse with my offhand attack is why I doubted taking Hex. I think it is worth the set up time at first, but once I get Lifedrinker, I think it could safely be traded out for something better. AoA was a definite, it makes me a lot tankier, and gives free damage since I am only the 2nd melee character in a 6 person party. I didn't think of Hellish Rebuke, that's a good idea since I don't have any reaction options, unless I take Warcaster. If I can afford it, I may take D/D just for the flavor of ShadarKai, doubt I will use it because of the effect on my party. Not sure what Shadow Blade or Shadow of Moil are yet, don't have XGtE until Christmas, I assume they're in there?

Definitely taking thirsting blade and Lifedrinker eventually, and Imp Pact Weapon is required to gain the benefits of the +2/+3 versions later. The UA Invocations aren't allowed outside of these however, phb and xgte only. Same with spells. I was debating Eldritch Smite for when I crit a big bad and can blow a slot to delete him, but I might be pretty heavily invocation taxed until much later.

We did roll stats, and I get 10 13 14 15 16 17 before racials, as well as a free Feat at level 1 in exchange for VHuman being banned, so I'm likely starting with Elven Accuracy and a 20 Cha. (5th level start if we do the background, character portrait, character miniature extra effort, which I have all done). I basically don't need to buff any other stats other than Con maybe, so I can pretty much take all Feats for my ASIs, so war caster, resilient, dual Wielder, medium armor master, lucky, or Alert and any others are on the table for possibilities.

What about multiclassing options? I technically only need 12 or 15 Warlock to get all the relevant invocations, so assuming we make it to 20, I have 5 to 8 levels to play with. I was already thinking of either BM, Swashbuckler, or some flavor of Paladin, likely conquest, but wasn't sure.