Cray Elemental (クレイエレメンタル Kurei Erementaru) is a clan. All Cray Elemental cards are treated by the rules as being of all clans and nations, and as a result, Cray Elemental cards can be used in any deck regardless of clan. Cray Elemental cards exist in grades 0 to 2, as well as as grade 4 G units, but there are no grade 3 Cray Elementals and only one Cray Elemental trigger unit, making it impossible to build a Cray Elemental deck. Rather, Cray Elemental cards are meant to be accessible to all decks. Cray Elemental cards have a wide variety of narrow and specialized effects, including effects which are meant to counter specific effects and game states, giving all clans the means to counter them when necessary.
The Cray Elemental concept was first introduced with Harmonics Messiah, which has a CONT ability that states that it belongs to all clans and nations, and cards with the printed Cray Elemental clan were introduced soon after, in G Booster Set 1: Generation Stride. Originally, Cray Elemental cards had a CONT ability like Harmonics Messiah, but due to a rules change on June 2, 2017, being part of all clans and nations became an inherent property of all Cray Elemental cards. This means that, while Harmonics Messiah can lose all clans and nations due to the effect of Exorcist Mages, Cray Elementals cannot.
Who are the Cray Elementals? (October 9, 2014)
Cray Elementals are spirits born together with the Planet Cray. They are originally formless concepts known as "mana" or "energy", whose existences could only be perceived by high-ranked units like Nobles and a portion of dragons. However, influenced by a great power that was brought to Cray, some Cray Elementals gain their forms. They respond to the wish of units residing on Cray and lend out their power.
Who are the Cray Elementals? (October 30, 2014)
Cray Elemental is the general term to describe spirits possessing composing elements of Cray. The representative elements are fire, water, wind, earth, light and darkness, which is hosted by numberless spirits. Myriads of minuscule Cray Elementals fuse together into a massive complex known as "Elemental Origin", and these beings have power so enormous that can even influence the planet itself. Originally, they cannot be perceived except by high-ranked beings, like a portion of Nobles and Dragons. Nonetheless, the report of witnessing Cray Elemental-like spirits has been increasing gradually since the emergence of "Stride".