Do you like the idea of Shards?

[OldTrees]

Shards are nice, they give a different flavor in the game (that you don't need a specific element's quantum to use it) and that is good. Just needs balance. But I dislike the part where the effect is "do more if mark is  ", "affects    creatures only" and whatever mark-related effect just because elemental shard whatever thematic thingy. It just looks too much like a card game we all know that has cards that favors dragons just because they're dragons and offers a card that counters ONE card. I actually expected better ways to make these shards match an element, like a shard that gives bonuses every time you draw, a card that amplifies healing, one that affects immortal creatures (okay. SoW got that right, but only SoW) and other things. It's just too... weird.

The thematic issue is rather important. There is a reason why some cards are  and some cards are not. Other cards gives all elements access to the ability. Thus elemental effects on other cards need to reference the powering element in some form or another. This is one of the requirements for having distinct elements. Rather than the pitiful excuse Yugioh had. These loyalty cost mechanics are one more way of differentiating the element system of EtG from Yugioh.

PS: Your examples would make terrible Other cards because they require being combined with an Elemental card of specific subsets of elements. They would in most cases be better off as Elemental cards. (SoW is a borderline case)

PPS: In most cases Magic the Gathering is a better comparison.