Learn Japanese with Anime - You're Already Dead

Analysis

おまえ is a second person pronoun “you” which is usually used for equals or inferiors in males speech. It’s used either when you’re looking down on someone or showing your intimacy for closest friends or your beloved person depending on the situation. But there are girls who hate being called おまえ so it’d be better to stay away from this word. Basically it’s used by men but you occasionally hear it from a girl who is boyish or bossy.

は is a particle which indicates the main topic of a sentence. It shows what Kenshiro is talking about right now and it’s followed by the explanation of the topic.

もう means in this situation “already” which emphasises something was completed before the present time.

しんでいる consists of て-form of the verb しぬ meaning “to die” and いる originally meaning “to stay still”. It describes an ongoing state resulting from the earlier action. So in this case, he died at some point and his state of being “dead” continues as the result of the action “die”.