Would it be a good idea to have a rareless way to generate shards, like nymph's tears generates nymphs in a rareless card?
Yes, provided such a card serves a secondary purpose like Nymph's Tears and if the alternate cost was balanced relative to the shards.
Nymph's tears is an alternate cost and a Pillar PC.
In fact, Shard of Integrity is begging for such a card to be made.
Would Glass Shard (http://elementscommunity.org/forum/index.php/topic,35283.0.html) be a good example of such a card?
Also, what are some good alternative effects that you feel would work with Mark Upgrades (http://elementscommunity.org/forum/index.php/topic,37370.0.html)?
No Glass Shard resembles Nymph's Tear too closely and did not adjust to the new cost range. (7
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/8-9
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-> 6
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/~5
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?)
Alternative effects for Marks?
The current idea is +5 quanta +5 hp when a named card is played by the opponent.
I feel this idea is extremely situational. Remember the old Purify? It was useful against 2 cards (Chrysaora and Poison). Now to be fair Purify cost a deck slot that the mark doesn't. However if there are alternate effects then this Taxation effect will cost a deck slot relative to the other abilities. This extremely limits the design of alternative abilities.
I would suggest skills of a quanta value of 0-1.
Example
Pendulum mark (choose 1 element in the trial and 1 at deck building)
Growing mark (it would increase in size every [balanced number] of turns)
Shard master (fools mark dependent shards)
Alternatively the trial could offer the ability to sacrifice the quanta generation for another ability.