So before I get into the details of the build, here are a few parses buffed and un-buffed to show you what this build can do. Sorry if I've missed anything in this guide, enjoy.
Parse 1: GROUP BUFFED Lambent Centurian (note that this was not setup with team spamming master architect set on me. This was with 0%up-time on major slayer... unlike other people's parses.
Parse 2: SELF BUFFED 3mil HP target dummy
Parse 3: SELF BUFFED 6mil HP target dummy
Bar setup
Bar 1:
Surprise attack
Rending slashes
Relentless focus
Deadly cloak/ Vigour
Killer's blade
Ult - Incapacitating strike
Bar 2:
Poison injection
Endless hail
Razor caltrops
Leeching strikes/ Reaper's mark/ Mirage
Rearming trap
Ult - flawless dawnbreaker
Rotation
Endless hail > Clatrops > Trap > poison injection (as you swap bar) > Rending slashes > from here on re-apply blade cloak when needed, spam surprise attack (or killer's blade below 25%) and use assasin's scourge shots whenever you get them. It's very important you light attack in between EVERY ability, you must get 2 assassin's scourge shots within each relentless focus buff. Re-apply relentless focus after the second shot and keep leeching strikes buff up for sustain if you're using it. Use incapacitating strike ultimate at the start of a front-bar rotation for max dps. This build is not for people who have problems light attacking or tracking buffs.
Gear setup 1: Trial buffed
Gear setup 2: Small group, solo play and trial penetration support.
Krahgs or Velidreth? Sharpened or precise? Night mother's or Briarheart?
It all depends on your group penetration support and CP's into penetration. I strongly recommend calculating your weapon penetration before deciding which sets/ traits to use. In most cases, you will want to use penetration traits/ sets for solo and small group content. Most veteran monsters have 18200 resistance.
Why no VO weapons?
Stamblades are not heavy attack builds, having the 8% stamina cost reduction on both bars really helps therefore you need the set working front and back-bar. Briarheart and MMG are proc sets which, once applied, will work on both your front and backbar.
Why briarheart and not hundings?
If hundings was to work on both your front and back-bar then sure, it would be more dps. But with this build we need VO working on both bars which means we would need our front-bar weapons to be apart of our secondary set. The second reason is the healing it gives (627 health for each critical strike), every bit of survivability helps. If you cannot obtain briarheart or simply just want to use hundings then use it instead, there will be little difference.
Champion points
The Ritual: 49 Mighty, 40 Thaumaturge, 52 Precise Strikes, 37 Piercing (You can change this depending on how much penetration you need)
The Attronarch: 40 Master-at-arms, 2 physical weapon expert
The Apprentice: None
The Shadow: 45 Tumbling, 30 Shadow Ward (Treasure hunter passive)
The Tower: None
The Lover: 75 Tenacity, 70 Mooncalf
The Lord: None
The Lady: 49 Hardy, 49 Elemental Defender, 48 Thick Skinned
The Steed: 31 Ironclad, 43 Spell Shield
Race: Redguard
Food: Stamina and Health resource
Mundus stone: Warrior (Lover if you need penetration still)
Self buffed stats (Trial setup)
VMA score with this build (solos setup)