Right now, the order of events for a turn is as follows:
1.Draw Card
2.Play/Discard/Use Skills/Use Items
3.'End Turn'
4.Creatures Attack
5.Poison Damage to Opponent
6.Pillars Generate Quantums / Healing Applied to Self
7.Dimension Shield Depletes
8.Weapon Attacks
9.Mark Generates Quantums
Let's suppose I have 100 HP, but 3 poison in me, and 1 SoG out. In the next turn, when I kill my opponent, if he dies from poison, creatures, or spells, I cannot get Elemental Mastery, because I will only have 97 HP due to the poison in me.
However, if I manage to strike the death blow with my weapon, after my Shard activates, I will get my 5 healing, and get Mastery.
Elemental Mastery, which basically doubles the value of a win, is too important to be left to a loophole like this.
I propose healing be moved to the VERY end of my turn, so with healing I get Mastery even when poisoned, OR move my weapon attack to take place before the healing, so there is no backdoor to get mastery through a lucky strike when poisoned.
Thanks for your attention.