It's true that these are the only variations of symbol that will appear, but once you get into the Rare class of cards there are a number of different ways that the card will represent itself
No extra costs, no prerequisites or conditions, just one card, one mana, four damage
This is semi-officially known as Contact Fusion, since it appears on the flavor text for Elemental HERO Neos, but not on cards that use it or in any rulebook
You can swap in a few stronger Water-type cards from booster packs (not included) to enhance your deck's power
Free, no login
Kangee, Aerie Keeper Kangee, Aerie Keepers value hangs on how many feather counters it has, and thus how strong other fliers are beside it