A Certain Magical Index, Vol. 20 (manga)

Accelerator begins his first mission for the secretive organisation known as Group. The task appears straightforward: eliminate the rebellious Level Zero group, Skill-Out. However, as he delves deeper, he encounters unexpected allies and mysterious benefactors, complicating his objectives. The emergence of a new faction adds further tension to the situation. As conflicts escalate, tensions rise in Academy City, setting the stage for an imminent confrontation.