Arata: The Legend Vol. 19 (manga)

Isora, one of Arata Hinohara's deadliest enemies, has stolen his ability to speak and now confronts him with life-or-death choices that challenge his devotion to his friends as well as their devotion to him. If any one of them fails to make the right choice, it could be all over! Even Kadowaki, once Arata's friend from school and now out to avenge himself on Arata for imagined hurts, finds himself facing Isora's test. Will he be able to look past his misguided hatred in order to deal with a real threat, or will he cling to it and doom them all?