Comments in order of presentation
Entropy: Interesting, though Pandemonium on a stick might be too powerful
Death: Target creature is killed regardless of HP, etc? While the effect is powerful, the cost makes it rarely usable
Gravity: Nova on a stick. Does it interact with the Nova passive (2 Nova+DM creating singularity)?
Earth: increase skill cost or lower ATK. Lightning is powerful enough as it is, a stronger version on a stick is too much
Life: Any? Would that be all, a random one, or is it targeted?
Fire: RoF on a stick is just as powerful as Pande or Lightning
Water: The Flood interaction is interesting, but "free" Purify for all your creatures...
Light: How would it deal with instant kill effects (Devour, your Reaper)?
Air: Upped could be nerfed, considering how you will create flying Shriekers and such it doesn't need to do so much damage by itself
Time: No Graveyard
Darkness: Interesting one
Aether: unupped is okay. Upped...Fractal Tulpa *shudders*
Overall: interesting ideas, but mostly need more work. Good job though!
Wise observations. I will modify the cards as soon as I get other comments.
Entropy: Interesting, though Pandemonium on a stick might be too powerfulFair enough, but its random and not always useful effect, I guess, counterbalances it.
Death: Target creature is killed regardless of HP, etc? While the effect is powerful, the cost makes it rarely usableI didn't want it to be too OP. It would work great with the interaction between Schroedinger's Cat and Soul Catcher, though.
Gravity: Nova on a stick. Does it interact with the Nova passive (2 Nova+DM creating singularity)I didn't think of it, but rather than interacting with Nova, I'd balance this skill with the sacrifice of some health (either of the creature, of the player or both).
Life: Any? Would that be all, a random one, or is it targeted?It influences all of the enemy creatures. I have the feeling that this skill is a little OP. Perhaps making Nature's Wrath easier to kill or increasing the cost of the skill would balance it a little.
Fire: RoF on a stick is just as powerful as Pande or LightningThe Efreet can be easily killed by any CC, beside Lightning Storm. I think that balances the advantage given by the skill.
Water: The Flood interaction is interesting, but "free" Purify for all your creatures...Perhaps it could be a reduced version of Purify (only +1 health per turn or with a duration of just one turn).
Light: How would it deal with instant kill effects (Devour, your Reaper)?Instant kill is not truly "damage", hence the Peace Herald wouldn't be able to prevent it. It doesn't prevent death, only damage.
Air: Upped could be nerfed, considering how you will create flying Shriekers and such it doesn't need to do so much damage by itselfYeah, it makes sense.
Time: No GraveyardToo bad at the moment there is no Graveyard, although it might be implemented (provided Zanz ever comes back or makes the game open source). It would open plenty of new possibilities and would add more deepness to the game.
Darkness: Interesting oneYeah, I find the concept of this card quite balanced and useful at the same time. It turns Holy Light into a not situational CC spell, which is a great thing.
Aether: unupped is okay. Upped...Fractal Tulpa *shudders*Silly me for not considering this. It would be enough to make it in a way that Tulpa can't be the target of Fractal, otherwise it would be insanely OP XD. I like the concept of this card because it's meant to work
against"swarm" decks when unupped and
within "swarm" decks when upped.