Mosaic Martial Arts Assassin Build Guide - D2 Resurrected
The Mosaic runeword solved Martial Arts' biggest problem — charge decay — by refreshing charge-up on every hit, turning Phoenix Strike/Blade of Ali/Dragon Talon combos into an always-on top-tier clear speed machine. Full stats, skills, breakpoints, gear tiers, merc setup and farming routes inside.
Build overview
Martial Arts assassins spent years fighting their own mechanic: charge-up skills (Fists of Fire, Claws of Thunder, Blades of Ice, Cobra Strike, Phoenix Strike) decay if you stop attacking, so any pause in combat forced you to rebuild charges from scratch. The Mosaic runeword (Sur + Ber + Jah + Sur + Jah + Ber, requires two claws) fixes this outright — while wielding a Mosaic claw, all your Martial Arts charges refresh to full and never decay as long as you keep attacking, and it also adds significant +skills, IAS, and FHR.
Pros:
- Effectively infinite charge-up combos once Mosaic is equipped — no more decay punishing you for repositioning
- Extremely high +skills from the Mosaic claws (up to +6 Martial Arts per claw in a Feral Claws base) push damage far beyond a standard Phoenix Strike build
- Fast, mobile, dual-elemental clear speed thanks to Fists/Claws/Blades finishers plus a Phoenix Strike detonation
- Great against most content since the build can layer fire, cold, and lightning charge-ups depending on what's resistant
Cons:
- Mosaic is one of the most expensive runewords in the game (two Sur, two Jah, two Ber) — this is a currency-heavy endgame goal, not a starter build
- Claw base requirements are strict (needs specific claw types for max sockets/ELvl) which adds to the cost
- Squishier than a trapper — you're in melee range, so life and resistances matter more
- Skill/combo execution has a learning curve compared to point-and-click trapping
Stat allocation
- Strength: enough for your claws and armor — usually modest since claws are light.
- Dexterity: enough for max block with your chosen shield/claw combo, then more for attack rating if you have leftover points; Assassins get bonus AR per dexterity point which makes this cheap to satisfy.
- Vitality: most of your remaining points — you're a melee character and need the life pool.
- Energy: none. Mana comes from gear and Burst of Speed's cost is low.
Skill order 1-99
- Claw Mastery — 1 point (or a few more later; it's a flat AR/damage multiplier for claws worth investing in once core skills are maxed).
- Fists of Fire — max. Your primary fire charge-up.
- Claws of Thunder — max, or heavily invested. Lightning charge-up, good vs fire-resistant packs.
- Blades of Ice — 1-20 depending on preference; some builds max this instead of Claws of Thunder for the cold synergy with Phoenix Strike.
- Phoenix Strike — max. Your finisher: builds fire charge-ups that detonate into a massive AoE nova on your next attack after 3 charges, dealing fire, cold, and lightning damage combined.
- Cobra Strike — 1 point for the life/mana leech proc; more if you want sustain in melee packs.
- Burst of Speed or Fade — 1 point each for utility; Fade for resistance and curse reduction, Burst of Speed for attack/movement speed.
- Dragon Talon or Dragon Flight — optional 1-pointer for a gap-closer if your Mosaic setup leaves room; most pure Mosaic builds skip these to focus the charge-up trio.
- Weapon Block — 1 point minimum for survivability if you have spare points late game.
A typical level 90+ allocation maxes Fists of Fire, Phoenix Strike, and Claws of Thunder, with Claw Mastery around 15-20 and Cobra Strike/Fade at 1 each, adjusting the exact split between Claws of Thunder and Blades of Ice based on what immunities you're farming around.
IAS breakpoints (claw class, Martial Arts)
Martial Arts weapon speed uses the claw-class IAS table with the base Weapon Speed (WSM) of your claw type factored in. For a typical fast claw base (WSM 0 or better):
| IAS gear total | Frames per attack |
|---|
| 0% | 16 |
| 9% | 15 |
| 20% | 14 |
| 32% | 13 |
| 52% | 12 |
| 68% | 11 |
| 86% | 10 |
| 116% | 9 |
| 165% | 8 (near-cap, requires very fast claw base) |
Target the 9-frame breakpoint (116% IAS) for the best balance of speed and gear flexibility; some min-maxed setups with a fast claw base and Burst of Speed active push to 8 frames. Note the Mosaic claws themselves provide IAS, so factor that into your total before stacking more from gloves/belt.
FHR breakpoints
Standard Assassin FHR table (light armor assumed):
| FHR gear total | Frames to recover |
|---|
| 0% | 9 |
| 7% | 8 |
| 15% | 7 |
| 27% | 6 |
| 48% | 5 |
| 86% | 4 |
| 200% | 3 |
Aim for at least the 48% breakpoint (5 frames); Mosaic's built-in FHR plus a Verdungo's belt or a couple of rare FHR pieces gets you there easily.
Gear by budget phase
Note: this build is defined by reaching Mosaic, so "budget" and "mid" phases below assume you're playing a standard Phoenix Strike/trapping-adjacent Martial Arts sin while saving for the runeword, or running a cheaper claw setup in the meantime.
Starter
- Weapon: any fast ethereal claw pair, or a single Fascia's Hierophant / Suwayyah base with sockets for Shael
- Off-hand: matching claw or a cheap katar
- Armor: Stealth or a rare with resist/life
- Belt: rare resist belt
- Boots: rare FHR/resist boots
- Helm: Tarnhelm for early magic find and free casts, or cheap rare circlet
Mid
- Weapon: single or dual Fury runeword claw (Jah + Ber + Ist + Ohm) if affordable as a stepping stone, or well-rolled rare claws with +skills and IAS
- Helm: Nightwing's Veil for +Martial Arts skills and mana leech, or a rare +2 assassin skills circlet
- Armor: Duriel's Shell for cold absorb and resistances, or Templar's Might
- Belt: Verdungo's Hearty Cord for vitality and FHR
- Gloves: Bloodfist for +1 skills, or Gore Riders come later for kicksin crossover
- Boots: Gore Rider if you dabble in kicks, otherwise rare FHR/resist boots
Endgame
- Weapon: Mosaic runeword (Sur Ber Jah Sur Jah Ber) in two eligible claw bases — this is the build's defining item, granting massive +Martial Arts skills, charge-up refresh, IAS, and FHR
- Armor: Chains of Honor for resist-all and damage reduction, or Fortitude for both offense and defense
- Helm: Nightwing's Veil or a rare circlet with dual leech and resist
- Belt: Verdungo's Hearty Cord
- Gloves: Laying of Hands for massive fire damage boost (synergizes with Fists of Fire) or Bloodfist
- Boots: Gore Rider or War Traveler
- Rings: Raven Frost for cold-immune cannot-freeze plus AR, and a rare/SoJ second ring
- Amulet: Highlord's Wrath for deadly strike and +1 skills, or a rare +3 Martial Arts amulet
- Charms: Martial Arts skillers, small charms for resist/life, Annihilus and Torch
Push for 75% all resistances, the IAS breakpoint that matches your claw base, and as much life as you can carry — this is a melee build and you will be standing in the middle of packs.
Mercenary setup
Run the Act 2 Nightmare Might mercenary for the offensive aura boost to your melee damage.
- Weapon: Infinity runeword (Ber + Mal + Ber + Ist) if you can afford it — the Conviction aura strips resistances and immunities for your whole party, hugely boosting Phoenix Strike's elemental damage output. Insight is a cheaper fallback if mana is tight.
- Armor: Treachery for Fade proc and survivability, or Fortitude if budget allows
- Helm: Guillaume's Face for crushing blow and life, or Andariel's Visage for extra offense
Best farming targets
- Chaos Sanctuary / Diablo — the Phoenix Strike nova's mixed damage types plus Infinity on the merc make short work of Diablo's Oblivion Knights and Diablo himself.
- Travincal — dense packs of Council members die fast to Phoenix Strike's AoE detonation.
- Pit / Ancient Tunnels — good density and layout for weaving Martial Arts combos through packs.
- Terror zones — the three-element charge-up coverage from Fists of Fire, Claws of Thunder, and Blades of Ice means very few terror zones give this build real trouble.
- Uber Tristram — with Infinity support and a maxed Phoenix Strike, Mosaic sins are a viable (if squishier) uber-killing option.
Leveling route and respec timing
Level with Fists of Fire and basic claw attacks from the start — it's a strong, cheap-mana leveling skill with no charge-up penalty issue in Normal difficulty since fights are short. Grab Burst of Speed early for movement, Fade once available for the resistance boost, and start layering Claws of Thunder and Phoenix Strike as your Nightmare skill points come in.
Because Mosaic is such an expensive endgame goal, most players run a standard Phoenix Strike claw setup (rare claws, or a Fury runeword pair) through Hell difficulty and only swap to Mosaic claws once they've farmed or traded for the runes. There's no urgency to respec around this — the skill allocation is largely the same before and after Mosaic; the runeword just removes the charge-decay penalty and adds a wall of +skills, so plan your points as if you already have it.
Common mistakes and how to fix them
- Buying Mosaic claws before you have a plan for the rest of your gear. Mosaic solves charge decay, not your resistances or life pool — don't dump your whole budget into the runeword and then farm Hell in Stealth armor.
- Forgetting to actually build charges before engaging. Even with Mosaic, you still need to land the charge-up hits before Phoenix Strike's finisher triggers — walking into a pack and immediately expecting a nova with zero charges built is a common beginner mistake.
- Neglecting Claw Mastery. It's a flat, cheap multiplier to your claw attack rating and damage; skipping it to pump more points into Phoenix Strike is a net loss once you do the math.
- Ignoring Cobra Strike. A single point gives meaningful life and mana leech on your Martial Arts hits — without it, sustained melee fights against the elemental damage this build deals can drain your mana pool fast.
- Using a slow or wrong claw base for the Mosaic sockets. The base's inherent WSM affects your IAS breakpoints; picking a heavy claw base undermines the speed this build is built around even with Mosaic's IAS bonus.
For more on the pieces of this build, see the Assassin class overview, the Assassin breakpoints reference, the Mosaic runeword details, and the cheaper entry points in the Lightning Trap Assassin guide and Starter Trapsin guide.