Fire Spell Chieftan needs Help

this build was great through the acts, smooth af

https://youtu.be/WZEg3vGaVaM?si=afZuYNxGIHhP0gwH

but in low yellow maps with this current setup, It has issues with rares, and in equal level delve zones it basically gets popped by some encounters.

https://pobb.in/b2tZrr42vwu_

plz I haven't really played in quite a few leagues, i know i need some spell block, but I feel more like im just not doing enough dps?