|Master||Caro Ru Lushe|
|Japanese name||ケリュケイオン |
|First app.||StrikerS (ep.3)|
|Voiced by||Kaoru Edo|
Kerykeion (ケリュケイオン Keryukeion) is Caro Ru Lushe's Boost Device, specializing in mana augmentation. Scrapping the complex magic support functions found in regular devices, Kerykeion boosts Caro's own mana, and specializes in releasing it in the most suitable form for the task at hand. Her programming language is English.
| Standby Mode|
|Accessory with two small pink gems and wing-shaped ornaments, wearing on Caro's left wrist.||StrikerS (ep.3) — present|
| Active Mode|
|Appears as a pair of fingerless gloves on Caro's hands. When spells are cast, the crystals glow and stripes elongate.||StrikerS (ep.3) — present|
| Second Mode|
|The right glove grows a pair of light fins that allow mana acceleration. Shooting spells like Wing Shooter can now be used.||StrikerS (ep.21) — present|
| Third Mode|
|Each of the gloves grows a pair of light fins. Boosted Protection can be used.||StrikerS (ep.24) — present|
Kerykeion was tuned with two main points in mind: to reduce the amount of mana needed during Summoning, and to strengthen Boost magic. She plays a good role of a sensor to detect enemies and summonings. As for AI, Kerykeion is relatively amenable. In the words of the device meister Shario Finieno, the Lightning Squad devices are "pretty similar in personality to their users".
As Kerykeion is in the form of two gloves, with two support engines it can cast two different boost spells simultaneously (one Boost Up, one Enchant), known as Twin Boost (ツインブースト Tsuin Būsuto). It is first seen in StrikerS (ep.5), cast on Erio and Strada to increase their striking strength and cutting capacity respectively. It is then known as Twin Boost "Slash & Strike", being the combination of Boost Up "Strike Power" and Enchant "Field Invade".
- ^ Magical Girl Lyrical Nanoha StrikerS opening theme 1.