Mage/Dark Wizard Arcanist lvl 105 build (looking for end-game, any cost)

I've been trying to find the build I should go for when I get the emeralds for a super endgame build (through a lot of grinding). I would like to find a good, viable, and high-damage mage build (if possible), (no preferred subclass but right now I'm looking into Arcanist). Currently, I'm looking at Fatal builds, such as this one.
https://hppeng-wynn.github.io/build...Y0P271C0y1L1g00001006CC15150+0+0+0+0-lNnddU+5
WynnBuilder build:
> Cumulonimbus
> Soulflare
> Dark Shroud
> Stardew
> Summa
> Summa
> Lachesism
> Diamond Fusion Necklace
> Fatal [t6f6f6]
> (Has Tomes, double rainbow skill point)
This build (credit to DeltaWave as this is essentially an altered version of the Fatal build in the 2.0 mythic builds thread) has high damage, ok mana sustain (arcanist, so I should be fine), and good walkspeed. If someone could help me confirm that this would be viable, or improve it, (or suggest another build entirely), that would be greatly appreciated.

DISCLAIMER: this build has 2 mythics, but I don't care that much. Don't factor in affordability into this, I want a nearly unobtainable build to work towards getting in the future, as I'm not yet wealthy enough to get any of this.

thanks in advance
-Opinor/warpspeed

 

bump10char

 

I mean, it looks good for Arcanist :d