Hey, this is not a complete build, but pretty powerful defensive mechanic which makes you tankier, and replenishes mana almost instantly but you have to keep casting
The idea is using rip blood maxed out direction Marrow Drinker + Arcane Fortress (left and right in the tree). You absolutely need Hematology as well, to take advantage of your intellect.
https://imgur.com/6jgM2N5
Naturally you need minions to cast it on, using ‘Summon Wraith’ is the easiest. Please note you need several minions for it to work effectively
In the passive tree and items maxing out intellect is needed (since it boosts Hemathology and ward retention), also cast speed is recommended.
The rest depends on your other skills. I am currently experimenting with other skills (core being rip blood + summon wraith, I think I will go for mark for death + sacrifice or mark for death + harvest). Then spell damage is needed or dexterity, respectively.