Conjure lightning storms

This needs tweaking. In fact, damage reduction with resistances needs tweaking in general.

It's ridiculous that 70% resistance still spells insta-death when the level difference between monster and character is 5+. Even when at capped res, if the character life is less than 2k (e.g., 1.5k), a character with little or no ES is left with a sliver of life.

There something wrong with the equation, IMO. Factoring in level difference, res and defense, a capped character with decent Eva and Armour should still have quite some more life than drips in the life pool, especially when the character out-levels the enemy. As mentioned everywhere, the game favors energy shield too much over the other types. It would have been fine if all characters have easy access to ES but everyone knows that's not the case. Players have to go through a roundabout route for ES which usually entails sacrificing their character's strengths and thus making PoE2 even less enjoyable than it should be.

Again, we're all for a challenging game, but your (GGG) margins are extremely slim especially in light of the issue I reported earlier on effects / cues / telegraphs are not rendering in-game leaving nothing to react to and a dead character.