Balance, key words suggestions.

[Maximvs]

Keyword suggestions :

Duelist : This creature cannot be attacked by 2 or more creatures.
Opinion : This would force the opponent to use a spell removal from the hand along with a creature to deal with it, if he's mostly playing small creatures, while not bringing anything on the table if he already played a stronger creature. This is meant to transfer a bit of power from rush to midrange and also to drain the guy's hand from removal spells.

Cycle : When this card mills a card, it goes at the bottom of his deck instead.
Opinion : Milling is a horrible mechanic that destroys complicated decks but does barely anything to more simple decks, which goes against what a strategy game is supposed to be. This would be a great way to keep the new cards almost as powerful as they are without being overly obnoxious.

Jinxed : This creature cannot receive beneficial effects
Opinion : This would allow for the creation of creatures that would otherwise create major imbalances just because of another, single card. Has no effect on the current meta, only for the introduction of future cards.

Taunt : If the opponent attacks during his attack phase, he must attack this creature with at least one creature.
Opinion : This would be an option to survive rush without the use of spells, something this game really needs.

Suicide : If this creature was in combat this turn, destroy it and the creatures it was in combat with at the end of turn.
Opinion : Yet another way to deal with creatures without using spells, something this game really needs.

Degradation X : Once this card has activated X times, put it in the grave.
Opinion : This keyword could be used to prevent ridiculously high values from being reached. Tombs could spawn 5 zombies and then go to the grave. Thaumic reflector could duplicate 5 spells and then go to the grave, forcing OTH decks to spend a bit more cards from their hands and keep 1 or 2 charge left for their heals. Grand reunion could activate 5 times and then ... etc., wihle allowing other cards like chalice of yunx to remain for longer. Would be a key word for non creature cards.

Balance comments :
Opinion no 1 : The evil races have access to creature destroying shrines that are so much more powerful and handy than most good shrines. These shrines allows an evil deck to keep only 8 removal spells in their decks while good decks are often stuck having 12 removal or more just to compete against a rush deck that started the game. I suggest an increase of 1 turn to the cooldown of sanctum of the void and the assassin's guild.

Opinion no 2 : Certain cards are too powerful when it is in play more than once. Certain cards ups your winning chance from 50 % to 90 % or over by just being there twice or more. A true combo that favors intelligence over luck is supposed to come from at least two different cards. For this, I suggest making master tactician, flesh sculptor and curse of rysha legendaries.

Opinion no 3 : Currently, spellweaver feels very extreme. Most good decks either tries to compete for the board right away or plays a longer game, with ramp if possible, with creatures that has an effect as it enters play, while midrange is left in the dark because their creatures dies as easily and the midrange window of power only lasts about 3 turns. Beyond that, all the 4 mana, 4 level creatures are pretty much double in power. As rush is being gradually nerfed with better options against them, you will also have to nerf creatures with effects upon entry. Creatures like the succubus should be nerfed to a 2 hp drain, and others of their like as well, to make midrange more compettive.

Opinion no 4 : The nature faction is very underwhelming now, and needs some love. It has few really powerful creatures, and I understand how it could be over powered for them to have such. What I suggest is the addition of powerful creatures to their side that costs a very high amount of level investment. For example, a set of midrange elementals mixed of all factions ; 2 green 1 white 3 or 4 mana light elemental, 2 green 1 blue 3 or 4 mana ice elemental, 3 green 3-4 mana moss elemental, 2 green 1 black, 2 green 1 purple and 2 green 1 red versions. That would bring them some individually solid creatures that could not easily be splashed in any deck.

Opinion no 5 : Competing against a rush deck forces you to have at least 12 removal in a deck, because if you try to block a rush creature, he will simply destroy it with a spell and attack instead. Spell removals are not interesting cards in themselves ; they add nothing to your own combo, only disrupt the enemy's or put a dent in their board control. The game would be healthier, more interesting and there would be more space in a deck for combos if we could survive rush decks by other means than using spells and evil shrines ; we need better blockers and more cards that can shift the attacker - defender dynamic around.

Opinion no 6 : If we see a deck being played all the time, maybe it's a good idea to nerf it. The corruption faction is overplayed. It seems everyone shows up at conquest with one pure black deck for a reason. Corruption has received enough love as it is and it doesn't need any more power than it already has. It needs a nerf, somehow.

Other cards that needs a nerf includes :

Arctic Shelter : This card should not be more powerful than the nature specific version. I suggest increasing it's mana cost based on the cost of the creature bounced.
Totem of legends : This card draws too many cards on the long run. I would reduce it's energy by 1 or 2 points.
Reanimate : It should cost 4 or 5 mana for creatures with respective costs.
Gomur Ironbeard : it should not be able to select the same ability twice. 4 speed or 8 hp is too much.
Pandemonium of darkness : It's life drain should be replaced for something else. This game has too much life drain and face damage as it is
Midnight cravings : It should be changed again. Black can do so many things already, it doesn't need any swift.
Advanced Nefaros : his hero ability should have an increase in cooldown. It is very powerful as it is already.
Catacomb keeper : I would limit it's card draw to 3, because it is stupidly powerful in an Aamon, lord of corruption deck.