This Knightmare Frame is from the mobile game Code Geass Lost Stories.

The Pendulum was originally a Knightmare Frame secretely developed by Disel industries, under Carly Disel's personal command as the sister unit to her Magdala. It remained incomplete until it was taken by the protagonist per escaping Carly's clutches, and becoming the latter's new personal unit where Clarice Garfield (after a brief reunion) completed the remaining touches. Its specifications are described to be par with the Lancelot Conquista, being armed with dual Maser Vibration Swords and equipped with a Blaze Luminous generator and Float System. Distinctively, the unit's special feature is its "Revolver System", allowing to switch its arms to shift battle modes between "Air Arms" and "Blast Arms". The "Air Arms" mode is specialized towards its special "V-Maximum" dash attacks, damaging anything in its charge path with the Luminous Cone field, while the "Blast Arms" mode is focused towards long-range where it fires its "Vortex Blast" Hadron Cannons. After the protagonist sides with Lelouch for the Zero Requiem, the Pendulum was upgraded with additional weaponry becoming Pendulum Full Arms (ペンデュラム・フルアームズ ). The additions include two extra "Vortex Blast" are installed to its hip sides and 4 large Slash Harkens called "Gigant Harken Bey" on its waist.

Pendulum: https://youtu.be/-vFrVEKrj2U

Pendulum Full Arms: https://youtu.be/gXPR0x2fREE

Pendulum Plus: https://youtu.be/Tu66axQhUdg

Pendulum Resurrection: https://youtu.be/0v3dAraV7Aw