As one last follow up (as at this point this discussion is obsolete unless WoTC actually gives us another UA hexblade to try out and give feedback on), I tried to ‘fix’ their UA version of the hexblade without adding or removing much of anything, but just polishing its functionality a bit and just add some power to 2 specific features that did not scale at all and felt almost useless.
Hexblades Curse - lvl3
Charisma number of uses per long rest. Curse a target and get benefits against that target. Accursed critical: crit on a 19 or 20 (moved here from 14) Hungering hex: when cursed target dies, regain D8+CHA modifier hit points.
Unyielding Will - lvl3
Accursed shield: While concentrating on a spell, and not wearing medium or heavy armor or wielding a shield, you get a +2 bonus to AC. (Tied it to concentration and without range restriction on cursed target so it’s easier to turn on and maintain, also not limited by hexblades curse uses and stacks with light armor). Vengeful Hex: Whenever you succeed on a concentration saving throw, you may deal necrotic dmg to all creatures of your choice within 10 feet of you equal to D8+Warlock level. Once you use this feature you can’t so again until the start of you next turn. (Made it scale with warlock level to keep it relevant throughout the entire progression. Could be scrapped in favor of proficiency dmg on hexblades curse). Eldritch fortitude: Whenever you would fail a concentration saving throw you may choose to succeed instead and gain a number of temp HP equal to D8+warlock level. Refreshes on a long rest.
Malign Brutality - lvl6
Harrowing hex: After you cast a leveled spell, you may make one weapon attack as part of the same action (attack is made as part of same action so not to clash with hexblades curse, animate objects command timing and to make feel close to what other gish subclasses get). Hindering hex: when you hit the hexblades curse target with a weapon attack, it gets disadvantage on its next saving throw before the start of your next turn. Inescapable hex: When you put your hexblades curse on a creature, or as a bonus action on your turn, you may teleport up to 30 feet to an empty space within 5 feet of you hexblades curse target (teleports are cooler than anime running towards you target, plus the ‘straight’ clause on the UA wording made it weird to use and also provoked AoO. It foes require your BA for future uses, but I think it would be a good trade off for better functionality).
Armor of Hexes - lvl10
Dmg reduction vs cursed target (Unchanged).
Masterful Hex - lvl14
Lingering hex: If a creature cursed by your hexblades curse dies, you can use a BA to curse a new target on subsequent turns. This does not refresh its duration. (Instead of gaining back 1 measly use of the curse with magical cunning, restored ability to move the curse around to be effective against multiple targets. While at such late level this would probably be less useful, I think it’s still nice to have and ok as half of a capstone). Exploding hex: When you hit the hexblades curse target with a weapon attack, you can cause an explosion in a 30-foot emanation from the cursed creature. That creature and all creatures of your choice within the emanation take 4D6+warlock level necrotic, radiant or psychic dmg and are knocked prone. Refresh on a long rest or can be used with a pact magic slot (dmg increased and scales with warlock level to be kelt relevant and worthy of a pct magic slot if one decided to use it that way. Slow effect replaced with applying prone, meaning slow effect is better because this usually means half movement and adds utility because melee attackers get advantage until they get back up, which for a capstone I think it feels much more impactful)
Together with this, I suggest home-brewing armor of shadows to be 10+DEX+CHA instead of mage armor (all it means is that it grants +1 more AC at lvl4 and an additional +1 at lvl 8 if both feats are used to increase the Charisma score). Nothing too crazy IMO seeing as sorcerers got this and even bards got this this and I think it would be a gkkf change to make warlocks feel good about their AC without multiclassing (AoS assuming 14 DEX grants 15 AC at lvls 1-3, at which point the subclass comes i granting a potential +2 for an AC kf 17. At lvl 4 CHA gies to 18 and AC goes to 16 or 18 with accursed shield, and finally at lvl8 CHA goes to 20 and AC goes to 17 base or 19 with accursed shield, which can be further improved by investing in DEX if one wishes to do so, and I do no think these values are crazy our unbalanced)
Thats just my 2 cents. Hopefully WoTC can come up with something better in the near future.
As one last follow up (as at this point this discussion is obsolete unless WoTC actually gives us another UA hexblade to try out and give feedback on), I tried to ‘fix’ their UA version of the hexblade without adding or removing much of anything, but just polishing its functionality a bit and just add some power to 2 specific features that did not scale at all and felt almost useless.
Hexblades Curse - lvl3
Charisma number of uses per long rest. Curse a target and get benefits against that target.
Accursed critical: crit on a 19 or 20 (moved here from 14) Hungering hex: when cursed target dies, regain D8+CHA modifier hit points.
Unyielding Will - lvl3
Accursed shield: While concentrating on a spell, and not wearing medium or heavy armor or wielding a shield, you get a +2 bonus to AC. (Tied it to concentration and without range restriction on cursed target so it’s easier to turn on and maintain, also not limited by hexblades curse uses and stacks with light armor). Vengeful Hex: Whenever you succeed on a concentration saving throw, you may deal necrotic dmg to all creatures of your choice within 10 feet of you equal to D8+Warlock level. Once you use this feature you can’t so again until the start of you next turn. (Made it scale with warlock level to keep it relevant throughout the entire progression. Could be scrapped in favor of proficiency dmg on hexblades curse). Eldritch fortitude: Whenever you would fail a concentration saving throw you may choose to succeed instead and gain a number of temp HP equal to D8+warlock level. Refreshes on a long rest.
Malign Brutality - lvl6
Harrowing hex: After you cast a leveled spell, you may make one weapon attack as part of the same action (attack is made as part of same action so not to clash with hexblades curse, animate objects command timing and to make feel close to what other gish subclasses get). Hindering hex: when you hit the hexblades curse target with a weapon attack, it gets disadvantage on its next saving throw before the start of your next turn. Inescapable hex: When you put your hexblades curse on a creature, or as a bonus action on your turn, you may teleport up to 30 feet to an empty space within 5 feet of you hexblades curse target (teleports are cooler than anime running towards you target, plus the ‘straight’ clause on the UA wording made it weird to use and also provoked AoO. It foes require your BA for future uses, but I think it would be a good trade off for better functionality).
Armor of Hexes - lvl10
Dmg reduction vs cursed target (Unchanged).
Masterful Hex - lvl14
Lingering hex: If a creature cursed by your hexblades curse dies, you can use a BA to curse a new target on subsequent turns. This does not refresh its duration. (Instead of gaining back 1 measly use of the curse with magical cunning, restored ability to move the curse around to be effective against multiple targets. While at such late level this would probably be less useful, I think it’s still nice to have and ok as half of a capstone). Exploding hex: When you hit the hexblades curse target with a weapon attack, you can cause an explosion in a 30-foot emanation from the cursed creature. That creature and all creatures of your choice within the emanation take 4D6+warlock level necrotic, radiant or psychic dmg and are knocked prone. Refresh on a long rest or can be used with a pact magic slot (dmg increased and scales with warlock level to be kelt relevant and worthy of a pct magic slot if one decided to use it that way. Slow effect replaced with applying prone, meaning slow effect is better because this usually means half movement and adds utility because melee attackers get advantage until they get back up, which for a capstone I think it feels much more impactful)
Together with this, I suggest home-brewing armor of shadows to be 10+DEX+CHA instead of mage armor (all it means is that it grants +1 more AC at lvl4 and an additional +1 at lvl 8 if both feats are used to increase the Charisma score). Nothing too crazy IMO seeing as sorcerers got this and even bards got this this and I think it would be a gkkf change to make warlocks feel good about their AC without multiclassing (AoS assuming 14 DEX grants 15 AC at lvls 1-3, at which point the subclass comes i granting a potential +2 for an AC kf 17. At lvl 4 CHA gies to 18 and AC goes to 16 or 18 with accursed shield, and finally at lvl8 CHA goes to 20 and AC goes to 17 base or 19 with accursed shield, which can be further improved by investing in DEX if one wishes to do so, and I do no think these values are crazy our unbalanced)
Thats just my 2 cents. Hopefully WoTC can come up with something better in the near future.