"SXyz" an abbreviation of "Shining Xyz", is an Archetype of monsters that can be Xyz Summoned by Xyz Change, with the effect of "Rank-Up-Magic Celestial Force", and is closely tied to the Number archetype. Number monsters that are summoned through Shining Xyz Change or Shining Rank-Up are known as "Number S", or "Shining Numbers". These monsters are created through the power of light, formed via a bond between multiple individuals or through the fusion of Astral and Barian World energy.
Xyz Materials attached to "SXyz" monsters either resemble normal Overlay Units, or are reminiscent of miniature suns, which referred to as "Shining Overlay Units". Like monsters that can utilize Chaos Xyz Change, these monsters require an additional Xyz Material but with 1 higher Level in a regular Xyz Summon, since they themselves are 1 Rank higher than their respective original counterparts, with only a few exceptions.
Most "SXyz" monsters are depicted in environments filled with bright light, or emerging from a void of pure light. A majority of "SXyz" monsters have rather dark appearances, in contrast to the bright light that usually surrounds them, while, in contrast, "Number S" Monsters summoned through natural Shining Xyz Change tend to have both bright appearances and bright background depictions.
"SXyz" monsters summoned via "Rank-Up-Magic Celestial Force", due to it's existence being a union of Astral and Barian powers, have effects designed to neutralize threats, via banishing or weakening monsters, negating their effects, or just do something to negatively affect their foes. This serves as a link between the personality and/or needs of the duelist who summons said "SXyz". As a footnote, "SXyz" monsters usually require more than 1 Xyz Material be used for their effects, balancing them out in comparison to their " " counterparts.