|This article is about a/an transformation device in Kamen Rider Blade.|
- ―Transformation announcement[src]
The Transformation Belt Chalice Rouzer (変身ベルト カリスラウザー Henshin Beruto Karisu Rauzā) is a unique transformation device possessed by the Joker Undead. It allows the Joker Undead to transform into any other Undead when its respective Rouse Card is scanned. Thus, it served as the basis for BOARD's Rider System technology. The Chalice Rouzer is used in this way by Hajime Aikawa to transform into Kamen Rider Chalice by mimicking the Mantis Undead.
The Chalice Rouzer can be removed from the belt combined with the Chalice Arrow in order to scan Rouse cards for initiating special attacks instead of transforming into the associated Undead. This also allows the effects of Rouse Cards to be combined in Rouse Combos. This functionality became the basis for the BOARD Riders' Rouzers.
The Chalice Rouzer is initially green, as seen when it is worn by the Joker Undead in its normal form. After the Joker Undead scans a Rouse Card and transforms into another Undead, it becomes red. Both Hajime and Kazuma Kenzaki are seen with this version of the Chalice Rouzer. The Albino Joker possessed its own Chalice Rouzer, which is white instead.
The World of Blade version of Chalice Rouzer is instead another Rider System created in order to transform into the forms of the sealed Undead. Hajime Shijyo used it with the Mantis Undead Rouse Card to transform into Kamen Rider Chalice.
- The overall design of the Chalice Rouzer resembles a Heart, matching Hajime's choice of card suit. In-series, this is unusual as the Joker is able to transform into Undead of any suit. This is further complicated by Kenzaki and Junichi's Rouzer also heart-themed, despite them having no association with the Hearts Suit.