I was actually thinking of making it
and Elixir of Life, since water is regarded as the elixir of life, y'know, all life needs water and that kind of stuff. But I decided on
. Definitely life isn't the right element that's about nature, this is about immortality, it's supposed to be like a holy gift, so it should be
or
. Elixir of Life really was a serious belief in many ancient cultures in like India and China and such, so it should be called that.
So, it cannot take effect from Infect, Fire Shield, EE, RoF, Plague, Thunderstorm, Thunderbolt, Gravity Pull, Drain Life, Fire Bolt, Ice Bolt (aside from freeze), Otyugh, Rage Potion, Unstable Gas, Shockwave, (in the case of Death or Darkness) Holy Light. no way will that ever work without a cost boost.
Quintessence is Immune to everything on that list, including Eternity, Reverse time, Lobotimizer, Mind Flayer, Arctic Squid, Freeze, Congeal, Antimatter. The only downside is that it is untargetable and isn't immune to Fire Shield and Thorn Carapace. Is it really a huge buff? I'm not even sure where it's extremely useful. If a creature is too big, antimatter it. If it's skill is bothering you, lobotomize it. Reversing it is pretty much a hard counter, and Squid-lock works on it easily.
I fail to see how it is better than quintessence. Antimatter and Reverse time are MUCH more widely used than Fire Shield and Thorn Carapace.