Very little is known of the Shadow of Intent’s operational history before the Great Schism. However, at the start of the Covenant civil war it was seized by Jiralhanae forces and turned against the Sangheili fleet staged outside High Charity. As the Arbiter fought to stop the firing of Delta Halo, special operations commander Rtas ‘Vadum led a strikeforce aboard the ship to retake control.

Source:
https://www.halowaypoint.com/en-us/universe/vehicles/shadow-of-intent