Girag with "Simon the Great Moral Leader", "Comics Hero Legend Arthur", "Coach Lord Ultimatrainer" and "Mechquipped Djinn Angeneral" above him.
"C", short for and known as "Chaos" (
"Chaos" monsters are all Xyz Summoned by Chaos Xyz Evolution - whether naturally or by a "Rank-Up-Magic" card - by evolving a specific Xyz Monster. When compared to these base counterparts, each of the "Chaos" monsters can be Xyz Summoned normally using 1 more Overlay Units that their original counterpart, but they must be of the corresponding Attribute (for the naturally-evolving "Number Cs") or 1 Level higher (for the remaining "Number Cs" and all of the "CXyzs") than their base form.
Aesthetically there is always a large vortex in the background of a Rank-Up "Chaos" monster and almost all Ranked-Up monsters have a redish-purple glow emanating from their bodies.
The two sub-categories of "Chaos" monster all share a common weakness with others in their group. For monsters Summoned by a natural Chaos Xyz Evolution, their effects cannot be activated while the controller's Life Points are above 1000. Monsters Summoned by the "Rank-Up-Magic" Spell Cards, however, have two parts to their effects, the second half of which becomes unusable while that monster's specific base counterpart is not attached to it as Xyz Material.