Vision

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Created by a villain by the name of Ultron, we saw in Avengers, he was converted from Jarvis to Vision which was nice, we all loved having Jarvis around.
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In the movie, the mind stone is connected to his head, before Ulton can enter this body Jarvis is uploaded to it instead, which is considered helpful for the good guys.
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He then helps the Avengers defeat Ultron and teams up with to protect the world, which he paid the ultimate price on Wakanda where he lost his life to Thanos who extracted the Stone from his head and had total control of the mind stone thereafter.