Griffin Sky are unmanned mass-produced flying mobile fortresses built by the United Kingdom. A Griffin Sky is similar in shape to a wing glider, but it's 80 meters across. It's colored red and has silver parts reinforcing important structural parts as armor. Griffin Sky are meant to attack strongholds in the surface, so they cannot fly as high as an airplane, and as unmanned spiritual items they are not as flexible or practical as other manned mobile fortresses, but they are the best in the UK in linked attacks.
Carissa deployed around 20 Griffin Sky during the Battle of Buckingham Palace, having previously gathered them with the intention of using them during her fight with her mother, but the forces of Necessarius eventually managed to destroy them all, mainly thanks to the Saint Kanzaki Kaori and the mobile fortress from their allied witches, the Coven Compass.
Powers and Stats
Tier: Likely at least 7-B
Name: Griffin Sky
Origin: To Aru Majutsu No Index
Classification: Unmanned Mobile Fortress/Spiritual Item
Wielders: None needed as it's an unmanned weapon, but it can receive instructions from a human controller for improved performance
Attack Potency: Likely at least City level at max output (Carissa manually set them as Anti-Windsor Castle level, the Windsor Castle's stronghold-level defensive barrier has been described as being not inferior to Index's former Pope-class Walking Church, which has been compared to a nuclear shelter)
Speed: Unknown, but probably at least Supersonic (When they initially appear they are described as flying above Buckingham Palace in giant arcs causing roars and explosions through the air, and later one of them manages to hit Kamijou Touma without him managing to use IB to defend himself)
Lifting Strength: Unknown
Striking Strength: Unknown
Durability: Unknown, probably at least Large Building level (Kanzaki Kaori catched one of them by grabbing its shadow and slammed it into 4 others after spinning it like a morning star with her super strength to prepare an attack on Carissa, none of them were destroyed by the impact; another was shot down by a barrage from a Selkie Aquarium, a submarine mobile fortress; and others were one-shotted by the Coven Compass' bombardment spell, which is described as being intended to attack fortresses and to possibly hold more raw power than one of Kaori's attacks)
Range: Extended melee range (20m) with shadow lance plus up to 50 meters of altitude by flying (maximum altitude shown)
Weaknesses: They don't possess actual intelligence, so they need a human controller for complex decisions/operations; a sufficiently skilled/powerful magician can take advantage of the link between a Griffin Sky and its solidified shadow to affect the Griffin Sky; it can be brought down by the combined efforts of several magicians using the anti-flight spell at the same time
-Shadow Lance: A Griffin Sky's main form of attack is by using its shadow. The shadows rotates and takes a physical form and weight similar to a 20 meter knight's lance, turning deep red and floating just off the ground. The Griffin Sky then charges the enemy to hit them with the shadow lance, which moves in unison to the mobile fortress. Since the Griffin Sky and its shadow are connected while this happens, restraining the shadow's movements' will similarly restrain the Griffin Sky itself, and the same goes for someone moving the shadow. The Grifin Sky is implied to have a safety measure capable of severing its connection to its shadow if this happens (developed for the possibility of the shadow getting stuck on a solid fortress), but a magician like Kanzaki Kaori can use high level magic to prevent it from severing the connection. The Griffin Sky has two settings: automatic; in which it will analyze the target to calculate the minimum amount of strength required to destroy it and don't use any more energy than necessary; and manual; in which a human controller manually sets the level of strength to be used by the mobile fortress. Their level of strength probably tops at anti-Windsor Castle level, which is the level Carissa set them to after one of them failed to kill Kamijou Touma in its automatic setting due to an unexpected bug (likely caused by Imagine Breaker).
-Flight: Griffin Sky can fly at low altitudes above the ground. During the Battle of Buckingham Palace they flew between 20 and 50 meters above ground, it's unknown if they can fly higher. While this is enough height so as to become vulnerable to the anti-flight spell, the Griffin Sky comes equipped with a magical shield that protects it against this spell. However, a Griffin Sky can still be brought down by several magicians using the spell together, as it was shown that the collaboration between three Amakusa members was capable of making one Griffin Sky lose its balance, but not enough to bring it down.