What do you think about gemstones of diverse colors (Crimson, Aqua, Solid, Transparent) gemstones that have the capability of storing elemental familiars, in a similar shape the game Brain Lord does with the jade gemstones?

For Example, A Minor Aqua Elemental Gem (1s) It could catch/summon a water elemental(ally) when used, but the stone does Not dissapear, so you can use it again to store the elemental within the stone, to give it some time to regenerate.

Also, A Minor Elemental Gem (1s) would summon a regular Elemental, but a Major Elemental Gem (5s) would summon a Greater Elemental.