Barbarian in a thief campaign.

I would like some advice. I have never played a barbarian and the closest thing to a martial class I have played is a Ranger... so not too much experience. An upcoming/ planned campaign that I will be in is a Thief/ heist type campaign and so I chose to be a barbarian. My species is an Owlin and he comes from a village in the saddle of a twin peaked mountain. due to an event that happened he left to lead a sudo double life. On one hand he is a long-standing assassin ( the event happened 40 years ago)for hire who has rules against killing innocent, on the other hand he is a man who hunts down slavers and kills them and due to the fact that people only see a winged shadow and a feather that is left at the scene (a color other than his own so that is not a connection that can be made) they call him the Angel of Death. He has chosen to do the heist because he is looking to ultimately retire.

Now here is what I am asking. What subclass would be recommended? I like having options, I like having versatility, I like being able to be useful beyond "I hit, I do damage.". I am open to thoughts on all the subclasses (except Carrion Raven... I like the idea but its too busted) I am also open to Multiclassing into another class, but I would like to keep it to the more martial classes if so. as for the rest of the team composition, we have a kobald dragon sorcerer and a Rogue... (I say Rogue because I don't know fully what they are, Likely Mastermind, likely human, but Im unsure). I will say I have been looking at the Totem and Ancestral Guardian, but I am open to others.

A Barbarian isn't necessarily a bad fit, things can go wrong and you sometimes just need muscle.

There is a difference in effectiveness depending on the ruleset, however. What ruleset are you using, 5e or 5.5e? 5.5e's Primal Knowledge feature lets you make Strength(Stealth) checks while raging. (That's not a typo, it lets you use your STR modifier for Stealth instead of your DEX.)

2014 rule set. So 5e.

Not sure of 5e/2014.  Looked at rules for those barbarians.

... can't paste link.

Did a search using "barbarian 2014." On the search bar above.  Being an owlin, a couple may not work.

But maybe: 

Path of the Giant - Bigby Presents: Glory of the Giants

Path of the Storm Heralda - Xanathar's Guide to Everything

Shadow Gnawer- book of Ebon Tides

Ancestral Guardian is a good pairing with a melee-focused rogue. Zealot has a little bit of support at higher levels. Beast is gets an extra skill proficiency if you want to go that way. Path of the Giant is excellent for diverse options in combat. Beast Barbarian also has a few more combat options than the default.

A 2 level dip into Rogue or 1 level dip into Fighter can work well with Barbarian, but don't sacrifice Extra Attack. 

Some things to consider when playing a Barbarian in heist: 

- Danger Sense is fantastic for soaking damage from traps.
- Use your background to pick up useful skill proficiencies
- Bring lots and lots of ropes to help your allies scale walls etc...
- Focus on complementary skills that your allies are missing.
- Being able to hold a door closed is invaluable when heists go wrong.
- Learn the Grapple Rules! Being able to grab a guard and prevent them from raising an alarm is often better than killing them.