Do you like stealth gameplay? No? Well, neither do I!
For this reason, [Ash] was a frame I initially didn't care for, until I found this build here. [Ash] actually has solid baseline bulk, with 450 base hp, and by exploiting a number of cool synergies, he can become an extremely resilient melee frame. [Fatal Teleport] is a very cool augment, and lets Ash proc several great buffs at once with the right setup.

I run this build along with my:
Skiajati - BUILD COMING SOON
Daikyu stat-stick

With this setup, with every finisher you will:

• 1-shot basically any enemy: easily deletes heavy gunners over level 200 even without a combo built up
• Gain 1200 armor: Arcane Ultimatum will always proc on a finisher kill, giving a huge buff to Ash's survivability that's easy to maintain
• Become invisible: [Skiajati]'s passive gives [Ash] a window of invisibility that can be used to escape a dangerous situation or chain finishers without even being attacked
• Fully heal yourself: [Amalgam Daikyu Target Acquired] gives an amazing buff to this build: 3% lifesteal on your [Nikana]. This means any strike doing at least 53500 damage (which any finisher should) will fully heal you. Access to such consistent healing patches a major hole in [Ash]'s survivability

As far as build specifics, I've built to maximize durability while also adding high strength in order to guarantee 1-shots with finishers. The Umbral set is a natural, giving [Ash] an impressive raw HP stat and respectable armor. [Adaptation] gives him excellent survivability when combined with the huge lifesteal of this build. [Hunter Adrenaline] ensures that you can keep casting Teleport as long as you're taking damage, thereby letting you heal and reset your buffs on demand. [Fleeting Expertise] is a natural fit for the last slot, since [Ash] has no need for duration with this build, and it brings Teleport all the way down to 6.25 energy (thanks to the refund on kill from [Fatal Teleport]).

For Arcanes, Ultimatum is a cornerstone of this build, since it more than doubles [Ash]'s eHP and is very easy to keep active (just cast Teleport at least every 45 seconds). [Fury] nicely complements the melee focus of this build, and also increases the strength of your finishers. You could also consider Strike or Avenger depending on your melee build.

Why did I pick Skiajati for this build? There's several reasons:

• The stealth on finisher bonus gets great value when doing lots of finishers
• Being a [Nikana], it can benefit from the extremely strong (I would argue somewhat overpowered) Daikyu lifesteal, which gives Ash the self-sustain he otherwise lacks
• Since it's a status focused weapon, and heavily slash-weighted, it benefits greatly from Ash's passive which improves the duration and damage of slash procs
• I have a riven for it :)

If you don't want to use [Skiajati] or don't have a Riven and are willing to give up the cloaking bonus, Nikana Prime also works nicely, since it's also a slash-heavy [Nikana].