Assassin/Ninja Twf Cataclysm: 1.20.3 Friendly

This is the current build i'm running with my assassin, very tome heavy, as you need +9 sp with tomes. I got +6 from two weapon mastery and +4 from a guild tome.
https://wynnbuilder.github.io/index.html#4_07R0JX0Jh0QR0OS0K20ZR0og0QQ-b2C141V-a1g00010006C10036C
WynnBuilder build:
> Cancer֎
> Anima-Infused Cuirass
> Cinderchain
> Dawnbreak
> Diamond Static Ring
> Moon Pool Circlet
> Remikas' Authority
> Tenuto
> Cataclysm [t6t6t6]

 

Two more builds, no tomes required, and you can probably swap around some items (both of these are less tanky than the one above).

https://hppeng-wynn.github.io/#4_0K90RZ0r50QR0OS0OS0OJ0og0QQ062C1h1M061g000010036C
WynnBuilder build:
> Sparkweaver
> Medeis
> Vaward
> Dawnbreak
> Diamond Static Ring
> Diamond Static Ring
> Diamond Hydro Bracelet
> Tenuto
> Cataclysm [t6t6t6]
high damage, mild sustain

https://hppeng-wynn.github.io/#4_0K90RZ0DS0QR0K00OS02d0uI0QQ002C141S001g000010036C
WynnBuilder build:
> Sparkweaver
> Medeis
> Demon Tide
> Dawnbreak
> Intensity
> Diamond Static Ring
> Atlas
> Eyes on All
> Cataclysm [t6t6t6]
good sustain, less damage

 

I know you wanted twf but here is a twfa i made since you allready have the tomes
https://wynnbuilder.github.io/#5_0K90RZ0D40QR00vCI-10000MFlipped Lapis Ring0270540M0201G0V010n0k013530K00TN0og0QQ002C1f111L1g000010036C
WynnBuilder build:
> Sparkweaver
> Medeis
> Dark Shroud
> Dawnbreak
> Flipped Lapis Ring
> Intensity
> Dragon's Eye Bracelet
> Tenuto
> Cataclysm [t6t6t6]
All you need are two cosmic

 

https://wynnbuilder.github.io/#5_0K...010n0k013530OS02d0Ji0QQ002C1f111L1g000010036C
WynnBuilder build:
> Sparkweaver
> Medeis
> Dark Shroud
> Dawnbreak
> Flipped Lapis Ring
> Diamond Static Ring
> Atlas
> Contrast
> Cataclysm [t6t6t6]
this one has some nice life steal too

 

Wouldnt dragons eye and tenuto be better?

 

maybe, but i wanted to get more lifesteal there, and also get a bit more mana to deal with a more expensive miltihit (you can always use vanish-spin-spin more often)

 

Hmm yeah i understand, well as it often is with builds, its up to personal preference what you wanna use

 

the dmg goes down a bit too, but cata deals so much dmg that it doesnt really matter
but as you said, personal preference