There have been many debates on the quantity and effects of cards for a while....
Honestly, I would like to see more cards in general, by more as in double or triple the current count.
1.) I personally think each element needs it own personal spin on each core area of the game that many still have missing areas:
1x perm defense (salvanger, protect artifact)
1x perm control (steal, defrag, etc)
1x alternative damage (poison, spell, SoV, etc)
1x counter to alternative damage (purify, reflect, etc)
1x creature quanta gain (pests, flies, ray of light, etc)
1x spell quanta gain (nova)
1x spell damage source (explosive gas, fire bolt, etc)
1x AOE creature control (thunderstorm, pandora, etc)
1x target creature control (chaos seed, reverse time, etc)
1x heal form (heal, divinity, purify, etc)
2x shield types (life, light, death element examples)
1x multi-use spell (purify, acceleration, reverse time)
1x cross cross synergy card for each element combination, be it active ability or obvious synergy (Sundial, GoP + Nightmare, leaf dragon)
Until this is addressed, a big part of random encounters is simply what elements were selected, especially in mono or dual combos. I've posted in past accounts, many examples of mono decks that were simply unable to be beat (except by rng) by any mono deck of a specific element. Until then this game remains completely unbalanced. These core areas need addressed.
The examples above don't have to individual cards, for example, purify meets the heal, multiuse, and the counter to poison.
Each element's card respective cards should stay true to the element. Life, should remain the master of heal, no one should have any question the best element for healing is life. No one should have bigger damaging cards out of the gate than Fire. A good spell for fire, might be fuel, in which sacrificing a creature to a fire might offer some healing effect, similar to cremation. Respect to certain cards by ability should remain, for example, protect artifact is in effect the ultimate protection for perms, however lots of creative and less effective perm control can exist for example, time might do a time seal where the perm card has no effect but can't be targeted or removed from play for 2 turns.
The natural meta game radically shifts, and I know some people in the forums would threaten to quit but many, many more have already quit over this issues.