Since U50 it's been much harder to hit the doublestrike cap, specially if you're a barbarian since they notoriously get 0 doublestrike from their trees. There are two universal options to help with this: Rapid Slash (+20%) from VKF and Quick Strike (+25%) from TA or Henshin. However there restrict you to daggers and staves; the letter is best for barbarians and their THF synergies, and Sword to Plowshares got buffed in U51.
Pros:
- doublestrike cap
- 15% attack speed while standing
- 17-20/x5 threat range
- evasion
Cons:
- lower BDR
- light armor
- no class trance or capstone
Staff Barbarian
Barbarian 18 / Rogue 2
Stats: STR -> CON -> INT
Skills: UMD, trapping skills and intimidate.
Race: any works, I used shifter for Magic Fang and raging bonuses.
Feats: PA, THF line, Improved Critical: Bludgeoning, Overwhelming Critical, Doublestrike, Scion of Arborea. The rest is up to you, I took defensive feats eg toughness, epic toughness and the new improved barbarian defense.
Enhancements: core 34 FB / 11 TA / 4 Ravager.
ED: core 25 FotW/14 LD.
Items: I am using the following setup, there are better solutions using slotted sets and Windlasher's Ferocity but this was ready at my bank.
- Charune (artifact, piercing, STR, raging STR) [slot: ins STR and extra rages]
- Wildcard (PotF, false life, hamp, fortification)
- The Family's Blessing (PotF, enh DS, ins piercing)
- Legendary Hammerfist (PotF, Seeker, ins DS, ins deadly, Cannith Combat Infusion)
- Titania's Glory (MRR set, Crown of Summer) [slot: Litany]
- Legendary Belt of the Ram (MRR set, qual STR, CON, speed)
- Legendary Deepsnow Boots (PRR set, ins CON, qual CON)
- Legendary Cold Iron Bracers (PRR set, HP, ghostly)
- Legendary Ring of Prowess (MP, accuracy, deadly) [slot: dodge]
- Legendary Band of Insightful Commands (qual deadly, ins accuracy)
- Legendary Tharne's Goggles (Deception, TS, ghostly)
- Bloodrage Chrism (profane DS, profane PRR/MRR/DR)
- The Staff of Shadows
Doublestrike breakdown: 25 (quick strike) + 15 (artifact) + 15 (enhancement) + 6 (insightful) + 3 (profane) + 9 (EPL) + 9 (FotW) + 6 (LD) + 5 (epic feat) + 1 (rounding) = 94% doublestrike
This is usually enough to hit cap due to Cannith Combat Infusion, bard buffs or reaper boost. Permanent options are Scourge IPL, Bloodrage Barkers, 11 ap VKF dip.