Not Taking Any Damage
Recently stumbled upon the updated wiki page for elemental combos, and noticed the formulas for elemental mastery.
Here’s the curve for shield absorption power, by elemental mastery:
As you can see, shields should reach 100% absorption at around 400 elemental mastery. This seems a bit high, but only if you haven’t tried to max it. In fact, I didn’t need to enhance any of my artefacts. I used random 4* and 3* artefacts with elemental mastery, and a 2-set Instructor bonus (80EM) to get there.
The key of the build is the Magic Guide at level 50, which grants you 122 Elemental Mastery, which is more than some higher rarity catalysts at the same level.
Hope you can use this case study, which I think could be especially fun in coop, because you can shield your dps allies.