Okay, first off, there are a few things here which are not completely compatible with the current game mechanic - as in, they would need specific coding to the way the game works, for them to even be considered as options for future implementation. I'll go over a few here:
Note: Some may just need clarity, it's 02:30 here, and I'm sleepy.
Champion: Am I right in saying that this works like a Gravity Pull, in that, you cast Champion on yourself, and the next turn, all incoming damage is dealt to the Radiant Knight instead of to yourself? That is overpowered, Armaggios have 25 hit points for that very reason, this Knight only has 5. "if that source is a creature" - The radiant knight simply deals 5 damage to a target creature? Way too overpowered.
Purge: Remove all buffs and penalties from target creature; there is no variable in the game to remember what buffs go on to a target creature, for example, you play blessing and the creature gets +3/+3, that Cockatrice for example, simply becomes a 7/7 Cockatrice. It is not a Cockatrice /w Blessing attached. Similarly, Momentum is added as a skill which gives +1/+1, the ability Lobotomize removes the 'skill' Momentum, but does not remove the stat bonus.
A way to rework this, would be for it to work in a similar manner to Rewind Time; remove the target creature from play, and all its buffs, penalties, poisons etc. Except to not remove it, simply to replace it with the original card. I think that, as an alternative working to the mechanism could work.
Note: My knowledge of coding is minimal at best, I'm just speaking from experience from being on this board and community for a while and knowing what people have, in the past, shot down and/or flamed for being a 'nightmare to code'.
Pyromancer: Okay, a good concept and not too overpowered. Maybe make the upgraded version deal 3 damage to a target creature and 1 damage to the pyromancer?
Brimstone Devourer/Gobble: Cards cannot have two abilities. You suggest that this card is able for you to 1st sacrifice a card in play (presumably your own), then 2nd gain +1/-1 and then also destroy a target pillar. Just think about the clicking this would involve, in PvP you only get 60 seconds to do your turn... Click Devourer, Click Sacrificial Creature, Click Pillar to destroy. Nope, wouldn't work.
I think, as an alternative. Make the Brimstone Devourer like a Ignition Sprite (or something; see my note at the top about it being late and my brain going numb). As in, make it work like Aether's spark card, 3/0 stats, so you play it, it attacks and dies. Then, make it's ability, 'Sprites attack causes a random enemy pillar to be destroyed'. Finally, make the Sprite immortal, so that you cannot +0/+3 it with a Plate Armor and have a permanent creature with pillar denial.
Cinder Golem: An interesting concept, but there is a conflict in the mechanics. Sacrificing the Golem to play a spell less than his attack? The game does not have variables to hold specific details about creatures attacks, it also does not have the ability (as far as I know) to translate that into a quanta cost. A much easier work-a-round will be to give the Cinder Golem the ability Flame-Burst (again, sorry for the name), which destroys the Golem and gives you 5 Fire quanta?
Not sure if passive skills work in conjunction with activated skills - see my note somewhere on cards not having two abilities.
Burnout: An interesting concept, would work like poison but with a bonus increase to offense? Would become overpowered when used with Adrenaline - which literally causes your creature to attack up to 4 times a turn (triggering any effects which happen: "at the end of your turn"). But otherwise, perfect and I quite like it.
Maybe alternatively, make your Cinder Golem start with this ability? I don't know any more!
Blinding Radiance: Too weak, in a way. Black Hole, the new gravity card, absorbs 3 quanta per element from your opponent and gives you that amount back as life. So, theoretically: 12 elements x 3 = 36 healed & your opponent loses 36 quanta. Make this either deal more damage (risks being too strong) or make it burn some of your opponents quanta (too many denial cards maybe?)
Ashen Renewal: interesting in a way, but I am not sure if there is any method to re-shuffle the deck once a game has started, shouldn't be too hard to implement I'd imagine. Also the gain +1 extra card, what if you have 8 cards, eg. Start the game, opponent goes first, you have 7 useless cards and you draw Ashen Renewal as your 8th?
Combustion Sphere: Not sure there is a mechanic in-game for this to work, dividing total damage by total creatures can create 0.53 numbers which I don't think the game can handle, would these be rounded up or down? Which is more fair? And this card, although perfect for fire, would be better for another element - fire typically has low HP creatures.
Volcanic Ground: Again a nice alternative pillar. If anything I want to see 12 of these sorts of cards, one for each element - permanents not pillars though. And with an element specific ability
.
Hope this helps.
