|This article is about a/an organization in Kamen Rider Zi-O.|
- "We are Quartzer, the Wardens of History!"
- ―SOUGO announcing his organization in front of Sougo
The Quartzer (クォーツァー Kwōtsā) are a mysterious time-traveling group who appear in Kamen Rider Zi-O: Over Quartzer.
All of their members are men wearing attire similar to Black Woz, who later is revealed to be one of their members. Their leader Barlckx wears a red-color variant of the robe and sits on a throne.
Amongst the Quartzers are a select group of Ohma Zi-O-like Kamen Riders who are able to utilize the Ridewatch powers of Kamen Riders who were presented in the Heisei Era but not considered part of the Heisei Rider line-up.
The group was founded by the original Sougo Tokiwa. They intended to kill Krim Steinbelt before he creates the Drive System in order to erase Kamen Rider Drive and Kamen Rider Mach from history, thus negating the creation of the GrandZi-O Ridewatch.
- SOUGO Tokiwa/Kamen Rider Barlckxs (leader)
- Kagen/Kamen Rider Zonjis
- Jogen/Kamen Rider Zamonas
- Black Woz/Kamen Rider Woz (self-defected)
- Multiple Kasshin
- Several unnamed members
- The unnamed members of Quartzer are portrayed by the members of DA PUMP.