Assassin/Ninja Help How Would This Be Improved

I made this Nulli build because I'm thinking of buying one when market gets back.
https://wynnbuilder.github.io/#4_0Au0Pf09U0uD0K00TQ0OJ0og0Qo0k0v1h1Q0r1g000010036C
WynnBuilder build:
> Cumulonimbus
> Libra
> Rainbow Sanctuary
> Magnet Repulsor
> Intensity
> Draoi Fair
> Diamond Hydro Bracelet
> Tenuto
> Nullification [t6t6t6]
The ehp feels really low but I don't know how to fix it. Any way to make the ehp better without dipping below ~8.2k spins? Also no diamond fusion necklace or mythic boots please

 

Do you mind flipped lapis?

 

No I don't mind

 

k I'll try my best to make a build(not the best but I can try)

 

https://wynnbuilder.github.io/#5_0Au0Pf09U07W09q09q00zCI-10000QFlipped%20Lapis%20Bracelet0270550M0201G0V010n0k013530og0Qo0k0v211h1D1g000010036C
WynnBuilder build:
> Cumulonimbus
> Libra
> Rainbow Sanctuary
> Capricorn
> Black Catalyst
> Black Catalyst
> Flipped Lapis Bracelet
> Tenuto
> Nullification [t6t6t6]
less damage, but much more ehp and better spell costs, also capricorn can be swapped for magenets and powders I would advise water or fire because you have super slow attack speed, if rly want dmg put sp in str but def is much bettr