Is this build good?
https://tos.neet.tv/skill-planner#212bk.254585.2e317f5a95.1a3f9f55.8f9fcae5
I was told that hell breath is kind useless since you cant move while using it, that emental essence is not that relevant, and that mobs have a very high crit. resistance in end game, and then firefox is kinda useless.
What do you think about that?
HellBreath can be nice for cc and knockback. But not really worth more than 1 point.
Yes, Elemental Essence is not very useful.
Firefox sounds good and doing crits is not extremely hard when you get new Ichors.
I dont have Onmy now. Your Pyro looks good.
Could max Electrocute for more Hits, less points in Hail or maybe StormDust.
you can cover your crit rate with new equip lvl 430 option (which is crasy number compared to lower lvl) so, firefox still not a thing for boosting crit rate for fire-elemental only. other is fine, electrocute lvl 14 for max target (or 15 if you have divine might 24 hour / electrocute gem).
Which is better for this class? Staff + Trinket or Rod + Shield? And for armors, plate vs. leather?
for all DPS:
2Hand and Trinket. Leather
Yes you can’t move from the place you stand while using hell breath, but you can like move your aiming 360 while using it 
fire fox is kinda useless maybe, i do not rlly see the diference while is active maybe because my crit chance is not high as for elemental essence… how does that work ? does it power up the final damage if a skill makes elemental damage or just buff your elemental damage stats 
???
you see +50% when hitting monsters with skills if your skill has elemental advantage. elemental essence boosts that. and its attribute reduce the -% when disadvantage.
see ingame help “?” and “Incompatibility”
or https://tos.neet.tv/misc/damage-compat
or https://treeofsavior.com/page/guide/view.php?n=12
used to max it long ago, but its very situational and rare to get value out if it. for 10 points.
many people dont take it nowadays