EON KID

In a futuristic world, young Marty stumbles upon a bionic arm which endows him with superhuman powers and put him at the centre of a centuries-old struggle between good and evil. His teenager heart will now begin a long-way training together with two loyal friends: Buttons, his robo-puppy, and the brave Ally. (Source: Official website) — Description from AniList community (anilist.co).