Lswarm

"Verz" (ヴェルズ Veruzu) is a Duel Terminal archetype of DARK-Attribute monsters which was introduced in Duel Terminal - Sacred Star Knights!!. Despite being released prior to "Verz", the "Steelswarm" archetype (which is known as "Inverz" in the OCG) is a "Verz" sub-archetype. Thus, all "Steelswarm" monsters are supported by "Verz" support cards. The most significant feature of the non-"Steelswarm" "Verz" is that their ATK/DEF end with 50, and all known "Verz", except "Verz Golem" and "Verz Coppélial", are Level or Rank 4.

Members
Each non-"Steelswarm" "Verz" is based on a member of a previous Duel Terminal archetype, corrupted by the "Steelswarm" virus that was released from "Steelswarm Cell", shown in "Corrosive Contagion Infestation". There is a "Verz" counterpart for each Duel Terminal archetype except "Vylon".

From "Duel Terminal Overlay Guide 2".

Story
A crisis has struck the Duel Terminal world. Nearly all living things across the planet have been corrupted, their bodies warped, and their minds slowly seized by a desire to destroy that is so strong, it becomes impossible to interact with others. The elders of the planet linked it to ancient lore of an identical plague, and so dubbed the infection, and the infected, the "Verz."

Relationship
This archetype shares a close name with "Steelswarm" (Inverz, インヴェルズ), an archetype from the previous Duel Terminal story arc. They both consist of DARK monsters. Furthermore, the "Inverz" could be seen as a shortened version of "Insect Verz" or "Insectoid Verz", meaning the "Verz" virus might have come long before the "Steelswarm" did, and the "Steelswarms" are a heavily-infected species of creature. Even the "Verz" symbol can be seen as an outline of "Steelswarm" symbol (best seen on the horse of "Verz Thanatos").

Another possible theory is that the Verz virus is a defense mechanism the Steelswarm implement upon extinction that works to reconstruct their race. This can be seen by the Verz controlled Gishki Noellia's goal being to resurrect Steelswarm Hercules, the overlord of the Steelswarm.

It is also possible that with the destruction of the "Steelswarm" at the hands of the "Vylon", the virus then could have corrupted or even copied the other Duel Terminal archetypes.

In addition, "Verz" is French for "Worms". This may signify that their role is similar to the "Worms" in the previous Duel Terminal story as the first, horror movie-like antagonist ("Worms" being aliens, "Verz" being the zombie virus), followed by a holy/unholy antagonist that at first appeared to be an ally ("Fabled" and "Vylon"). This archetype could also be a reference to the Resident Evil series. This conclusion is supported by the fact that "Verz Ouroboros" and "Verz Thanatos" have similar names to bosses in Resident Evil. Also, "Verz Thunderbird" appears to be a "Mist Valley Apex Avian" infected with Las Plagas (if this archetype is a Resident Evil reference).More Parallels can be drawn, Las Plagas, Were buried underground by a Spanish Castellan, The Inverz, the carriers of the Verz Virus Were Sealed underground after losing against the Vylon.

They are not considered Dark Counterparts because they lack the attributes that compose it (Like sharing the ATK, DEF and level or rank with their Non-DARK counterpart, or having "Dark" in their name)..

Trivia

 * All Verz monsters concentrate on destroying monsters who have Levels. The Gem-Knight, Laval, Gusto, and Gishki lack Xyz monsters. After the Sacred appear, they combine their powers to destroy the Verz with Xyz monsters, who have ranks instead of levels.