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