I am considering doing a warlock (blade/fiend)(3 or 4)/barbarian (bear totem).
Here's the thought - while raging, the barbarian has resistence (bear totem extends that out to all non psychic attacks). If Armor of Agathys is used, all attacks take 5 damage as long as he has those temp hp (or 10 damage if used at 2nd level). Additionally, dark one's blessing grants 3-6 temp hp for every opponent he kills (understanding the temp hp don't stack). It seems like resistence would apply to the temp hp as well creating a nice hp buffer while doing damage to the opponents. It is also possible that Agathys could kill an opponent thereby granting dark one's blessing temp hp. Combine this with reckless attack and you kill more creatures while giving them more opportunities to hit you.
It's pretty likely I could get guantlets of ogre power added to this as well making Str a fairly healthy +4 rather than +1.
Thoughts on this build?
Also - if I go this direction, thoughts on off-hand - do I go two handed weapon with great weapon fighting (and possibly a level of fighter (or two)), two weapon fighting (again fighter dip might work there), Glaive (or similar) and polearm mastery, or shield and melee weapon?
Fred
A couple things to consider:
1. Keeping concentration going while in melee is difficult. Is the barbarian profecient in Con saves?
2. What character level do you get a second attack?
This idea intrigues me since I've played a barbarian for the last year and a friend played a blade/fiend warlock. His healing from dark one's blessing and Vampiric Touch has made the character very durable. I wonder how a barbarian would play with all of those abilities.
If you can live with that though...
I played this a bit, but only at level 3 (Barb 2/War 1). The thing you have to think about is that you can't replace your AoA temp hit points with DOB temps or you'll lose AoA. So you'll have that initial buffer of AoA and when it runs out you can start getting DOB temps. Now, here's the deal, at 6th level your 10 AoA temps aren't gonna last all that long even with resistance. Throw on levels of Fighter, and you're in the same boat, if not worse. Also, DOB works best the more Warlock levels you have, as will AoA cast at higher levels.
So if you really want the build to work you're looking at either shooting for at 9 levels of Warlock for those level 5th-level slots (25 HP AoA) and 10-14 DOB temps. Or... not worrying about DOB temps and shooting for a 3rd class and grab spell slots past 5th level. A potential 40 HP AoA is a pretty bad ass thought. Heck, a Barb 3/Bard 17 could cast AoA with a 9th-level slot!
Good thing Armor of Agathys doesn't require concentration and lasts an hour, huh? 
FelwredNew wrote:
You can't recharge AoA with the fiend temp hp though. They're entirely seperate.
I have the exact same plan with my current character. He's a level 4 Barbarian now, and going to 5 for the Extra attack, then all Infernal Warlock.
Someone else poined out that Armor of Agathys does not require concentration. Other spells that work well are Mirror Image and Fire Shield since they do not require concentration either. But What I've found from playing the Barbarian from level 1 is that once you are out of rages, the only thing you can do is Reckless Attack. I'm going with Warlock so I have something I can do when the rages are gone (or so I can save a rage for the boss fights). When we take short rests a Barbarian get nothing back...it's annoying to see the Fighter and Moon Druid in th eparty get all their combat boosts back while I get nothing. Warlock will give stuff back to help with this problem.
Oh, and from one of the errata damage is taken/absorbed/applied in this order:
1 - Flat reductions - Heavy Armor Master or Abjurer Wizard ward
2 - Resistance
3 - Temp HP
4 - Real HP
So, yes, Bear-raging will effectively double your temp HP's. I have talked our Bard into taking the Heroism spell...4 temp HP that refresh every round for a minute, doubled to 8hp with rage will help me get by until I get to Warlock. I am also planning in taking the invocation for casting False Life at-will...8 temp HP while you are walking around most of the time, and twice as effective when raging. it gives you a buffer until I can get the Infernal temp hp's going.
BTW - I am the party's tank, with the Sentinel feat. I am focused on being the meat shield...and the monsters oblige everytime I start using the reaction attack from Sentinel. I'm also considering a possible dip with a Favored Soul Sorcerer(Healing or War) to get more spells known, low level spell slots for buffing when out of rages, and meta-magic to cast some of the buffs as bonus actions.
The Abjurers Ward AoA combo is super potent. Add Bear resistance and you'll keep AoA up for tons of attacks. It's MAD as all get out, but you could do it with a normal Human and get some decent stats.
I am currently playing this class combination. The plan is 2 barbarian and 12 warlock (currently level 2/3)... then level as I feel like with at least 3 barbarian for totem path and then taking battlemaster fighter for at least 3 levels.
It works well as a very versatile character who has great option when not raging. The second attack doesn't come in until level 7 but at level 5 you do have 2 bolts from eldritch blast that makes it ok but not optimal at 5 - 6. The temp Hp gained on kill is amazing when combined with rage damage reduction. Its a fun class but very MAD. half plate is a good solution but your con or AC will suffer. The class is alot of bookeeping in the sense of what abilities you have at any given moment but can be very rewarding when it gets revved up. At level 14 with a 20 cha every kill nets 17 thp that makes up for the low con early on. Finally the dark blessind encounter power of the hellock is very useful when using GWF.
Danny_Montanny wrote: