Survivability as a Pact of the Blade warlock without multiclassing
I've got an idea for a slightly masochistic warlock; one built around Zhentarim Tactics: Whenever I'm hit, I hit back harder. Pact of the Blade/Greataxe for as much bang for the buck as possible with the ability to roll damage twice. Zhentarim Mercenary background, granting Zhentarim Ruffian, followed by Zhentarim Tactics at level 4. Fiend subclass to have a constant source of temporary hit points to survive the punishment.
My issue, and my question to more experienced warlocks, is how you survive as a straight class Pact of the Blade warlock. At best, I can get an AC of 16 from Mage Armor + Dex 16, but it never seems to scale outside of magic items.
When it comes to AC, I see three obvious solutions:
- Take a level of fighter for armor proficiency. That'd instantly give me an AC of 18 (Half Plate + Defense Fighting Style + Dex 14). This is the obvious solution, if there are no other good alternatives. Having Weapon Mastery in a few big weapons would be a boon, too. It would delay Zhentarim Tactics until level 5, and extra attack until level 6, though.
- Take Hexblade instead of Fiend, for AC 17 (Half Plate + Dex 14). It doesn't seem like a worthwhile trade, as I'd lose the thp I'd get from the Fiend subclass. Not to mention, Fiend is a much better fit for the character concept.
- Take Moderately Armored. The problem is that a) It doesn't increase Charisma, and b) it means I can't take Zhentarim Tactics until level 8, which practically invalidates the build.
I've tried to look at other ways to increase survivability outside of increasing AC. First and foremost ways that do not involve using my Reaction, as I want to use that for Zhentarim Tactics as often as possible.
- Dwarves gain +1 hp/level. Orcs can survive a fatal blow once per long rest. Sadly, Warforged is not a legal option. Are there other species that can increase my survivability?
- Lessons of the First Ones: Tough would provide +2 hp/level.
- Lifedrinker can provide some sustain, but that's not available until level 9.
- Armor of Agathys provides thp at the start of each fight, which is helpful before I kill my first target (or an ally kills one next to me), and works great with the 'you hurt me, I hurt you more' schtick.
- Obviously, hanging back and firing Eldritch Blasts increases survivability, but that's pretty suboptimal when it comes to damage, as I won't be taking Agonizing Blast. A better alternative would be to acquire a magic shortbow and bind it with Pact of the Blade.
- One with Shadows may allow me to start fights invisible, but it's not ideal to walk around invisible all the time in case a fight breaks out. I want my character to be attention-grabbing and boisterous.
There are some spells that increase survivability, such as Darkness and Mirror Image, but they take an Action to set up, which is often not ideal. If I have a round to prepare, I'd prefer to use one of my limited slots to cast Summon Undead, at least from level 5. Not to mention, if I've spent a slot on Armor of Agathys, I only have a single pact slot left. I want to be able to drop a fireball now and then without completely invalidating my build.
Are there other ways to increase survivability that I've missed, preferably ones don't cost a spell slot, an Action to set up or require a specific magic item? Bracers of Defense seems like a no-brainer, but I can't exactly count on getting it early.