New player here : ES / Divine shield

Hey everyone !

First of all, thanks for reading !

I'm a fairly new to POE and I have some question around ES / Divine Shield :

Is it possible / reasonable for you to build a Cast on Crit character around that keystone ( pref witch ), focusing ES / Armor / Block ?
I'm not looking for some millions dps build, but something beefy with OK / fast clear

I have in mind some cheap unique items like Aegis Aurora / Crown of the Inward Eye.

My "build" level 80 :
https://poeplanner.com/AgADABUAAwEAYwAPEbAULxdsGnIaNxsUHfQiLSRfJU8pvyypLdYv-DDvMVgysDPYOg07Dz06Qv5GBkdASi1Ms0zPTTBQrlSpVdZVMVhrXGpfQ2PnZFRmnmYBaghsGW0Pcqly5Xe7fNJ9pIAegpuCSIR9hQuMdoxGj_qPfZJvlCCVtJf6l2-YIZuhmzyemKyqrKevxbQstjG3OLd8ucXB88Ftw_bEisWKxhPIH9DQ0F7b59sj3IrfYuMi5Lzkz-UY7LDs6--K8S_1ovYy99f30voAAAYASBrYaaF-dJL8uyj0BwD2sfuwXbhPhqtqRHu-19LfJjZr_QmYlBG5du6SBAAA______________________8AAAIAAAADAP____________8AAAAAABQAH4sIAAAAAAAAAwMAAAAAAAAAAAA=

Bye, have have a nice day !

PS : English is not my native language, sorry if i'm not clear.
PS2 : I ask here, because i didn't find information.