|Other names||Knight Zest|
|Species||Human (at birth)|
Artificial Mage (clone)
|Date of birth||uncertain|
|Date of death||0067 (original)|
|Affiliation||Ground Armaments Service (formerly)|
|Rank||1st Air Captain (formerly)|
|Japanese name||ゼスト・グランガイツ |
|First app.||StrikerS (ep.6)|
|Last app.||StrikerS (ep.25)|
|Voiced by||Masaki Aizawa|
His first name is presumably a reference to the Honda ZEST.
As a high-ranked Ritter, he also has a honorific title as "Knight Zest" (騎士ゼスト Kishi Zesuto), just like "Knight Carim".
Zest is a former friend and Ground Armaments Service comrade of Regius Gaiz but was ultimately betrayed by him. While working with his subordinates Quint Nakajima and Megane Alpine in the investigation of what was known as the Combat Cyborg Incident, Zest ignored an order from Regius to back off the investigation. As a result, the three were killed by the Numbers, and Zest was used as the base for an Artificial Mage.
The "reborn" Zest is imperfect in the form of health complications that will eventually take his life, and he takes the time he has to hunt down Regius, wanting to know why his team was "sacrificed". In the end, he never gets his answer, as Due takes the opportunity to kill Regius. However, Zest kills Due in revenge, and chooses to die a knight's death at Signum's hands.
A practitioner of the Ancient Belkan magic system with Old Belka Ritter Rank of Over S (Air), Zest is extremely capable and powerful, and is able to stand his ground against opponents like Vita and Signum despite his degrading health.