Barbarian builds are pretty straightforward feat-wise and the main decision is which fighting style to use. I would suggest THF. It's easy, does good damage and has AoE built in. You can do either SWF or TWF though too.
Heroic: Two-Handed Fighting, Power Attack, Imp THF, Imp Crit: <weapon type of choice>, Greater THF. That gives you two choices at 15 and 18.
Epic: Overwhelming Crit, Perfect THF, Crush Weakness, Doublestrike, Scion of Arborea, Epic Fortitude (for reapers, if not going into R+, you can skip imo). That leaves choices at 24, 27, and 31.
I would stay pure Barb for a 1st life build. For trees, I would suggest FB, but there's also effective builds that use Ravager (
https://forums.ddo.com/index.php?threads/kalis-barbarian-ravager-melee-dps-build.479/). Occult slayer is a bit niche (
https://forums-old.ddo.com/forums/showthread.php/528488-Reaper-Endgame-Agile-Fat-Barbarian, dated but great build) but can be used.
The nice thing about Barbarian is that it has a bit more freedom for enhancement points than other classes imho. This does prevent you from getting a trance. As first lifer, I think that's prolly fine, but as you get more lives or advanced you will want to incorporate one in the future.
If you go FB, I would suggest something like FB (41 for capstone, extra crit, extra strike through, extra action boosts), HOrc or Dwarf (18), Vistani (8 for Haste Boost, need to get Barovia favor -- not hard). That leaves 13 pts which you can spend as you see fit. Falconry is good for 13 pts, but requires Free Agent favor or store. Ravagar has bonuses for Power Attack which is helpful. Occult Slayer has some defensive stuff built around Weapon Bond.
The one thing I would suggest thinking about as a duo team is how much defense you will need/want and then how to get it. Defense gets overlooked a lot, but 'dead DPS = 0 DPS'. The smaller the group and more/higher reaper you do, the more you will want to think about defense on a barb. Barb defense can be split across a few different considerations.
1) Hit Points. Barb's can have the largest HP pool of any class. That's really your first line of defense. You can see that in the Ravager build I linked above. He took Toughness, Epic Toughness and Legendary Toughness with his build w/ his extra feats.
2) DR. Barbs get damage reduction as part of the class and you can build on that with your epic feats, but taking Epic Barbarian Damage Reduction and/or Epic Damage Reduction.
3) Dodge. Barbs get uncanny dodge, so you can often build your dodge up w/ gear and some feat choices. I find in a smaller group dodge is a bit to rng for me if the group doesn't have cc. If your teammate has effective cc, dodge or ac don't matter much. Feats here would be Dodge/Mobility, maybe Elusive Target in Epic
4) AC. You can take Heavy Armor proficiency with one of your heroics feats. I spent a few early lives in Heavy Armor in a 3-man team and used the Sharn 3pc set. Worked pretty good imo and for my style.
5) Some CC. Stunning Blow can be very effective as a barb. You can compliment it with various enhancements to make it even more effective. Very fun to knock a mob out and then obliterate them as helpless.
If you do run up to Epic, Fury of the Wild is probably your best bet for 1st life for destiny. Adrenaline is awesome, you can get your extra Strike Through (240+), and there are other good benefits. You can compliment that with Dreadnought for extra haste boosts and side benefits, and Unyielding Sentinel for defense. A lot of options for 2nd and 3rd tree but think your decisions above will make them pretty obvious.
Hope that helps. If you want a specific FB build, I think you will find one in Strim's hardcore builds on the old forums.
Https://forums-old.ddo.com.
