I like the idea of adding masteries, but I think they should require strategy and skill rather than rewarding just about every random thing.
"life mastery" -- ending with 100 life
"death mastery" -- ending with 1 life
"temporal mastery" -- ending with 8 cards in your hand
"poison mastery" -- ending with your opponent having 20 poison points
"creature mastery" -- ending with 15 or more monsters
"graveyard mastery" -- ending with 40 cards in your discard pile
--Life Mastery, like Elemental Master, needs to be full HP and not just 100 due to Shard of Divinity, but yeah, keep that. Also, I think Miracle should disqualify you from getting this rather than just make you heal 1 more HP.
--Death Master is just a luck-based thing based on what your opponenet plays (since creatures attack the same turn as played), I don't like it.
--Temporal Mastery is impossible like that; make it 7 cards but have a fairly low reward since this is easy.
--Poison mastery is cool but might be better at 15; that's a sign of a fast poison deck, whereas 20 usually takes an opponent Miracle or changing your playstyle just for the mastery.
--Creature mastery is good, but I think it might be better if based around the total number of creatures that entered play on your side to reward decks that use your own creatures for ability fodder (consume, mutation, immolation, boneyard) and not punish players that get hit with thunderbolts/rain of fire on the last turn.
--Graveyard mastery isn't easy enough to track and too easy to do.
Overkill Master-Win the game with your opponent at -40 or less Health (Would probably have to fix the bug that causes the turn to end early, but it would reward those decks that focus on damage, like fire)
Quantum Mastery-Win the game with a total of 100 Quantum or more (For Rainbow decks, mainly)
Round Table Mastery-Win the game with a Weapon, Shield, Pillar, and Other Permanent in Play (not sure which deck type this would help, but it is an interesting idea I think. Also, when I say Other Permenent, I mean something like Graveyard)
Buffed Mastery-Win the game with a creature in play that has at least 10 more Health than it came into play with (gives something for earth/blessing focused decks)
--Overkill Master is a good idea.
--Quantum Mastery should not exist like this, there's no real strategy being rewarded other than getting tons of quanta you don't need (which is actually more of a sign of an ineffecient deck). I think it would be great if it was for winning with exactly 0 quanta left of every type though.
--Round Table Mastery isn't rewarding good play, just good draws and the luck of not facing deflagration/steal/pulverizer
--Buffed Mastery is too focused; really easy to pull off with Scarabs and possibly Otyughs, really hard to pull off otherwise
Here are the ones I think should be added:
--Win without one of your creatures dying or using anything that comes into play as immortal
--Win with no creatures on the field for your opponent
--Win with zero cards left in your draw pile
--Win before ten (maybe less) turns elapse