My league starter in 3.24 that I decided to invest into since it felt like the ceiling was extremely high. I have geared it quite differently from everyone else as well so feel free to look at the POB. It can facetank every Uber mechanic i have tested so far, and it can become pretty much immune to chaos damage as well with the Uber Forbidden combo. I started doing Shaper carries on Day 3 and T17 carries Day 7 or so.
A cheaper alternative amulet is Eternal Damnation, works great in combo with Doppleganger's Guise, just losing around 15% max hits vs a good Utmost. Taking this template and swapping the ED should lower the build cost to less the 50 divs, and Enfeeble can be swapped out for Conductivity in earlier stages for DPS.
poe.nina: https://poe.ninja/builds/necropolis/character/Eishou/BluePrecum?i=0&search=name%3Dbluepre
POB: https://pobb.in/SlZN2FwCpAXo