Vision is a superhero from Marvel comics most often associated with the Avengers, originally built as a weapon by Ultron to use against the heroes Vision became self-aware and decided to cast aside his old master in favor of being a hero instead and has remained, more or less, a loyal member of the Avengers ever since. Vision is a synthetic being similar to a robot or android but is fully sentient, being capable of understanding and even feeling human emotions.
Vision's capability for humanity climaxed in many ways by him becoming the husband of fellow Avenger Scarlet Witch - although their relationship has struggled he has for the most part been portrayed as loyal, even amidst the chaos that is the life of an Avenger.
Vision's main power is his total control over his molecular density: Increasing it renders him invulnerable and augments his natural strength, while also making him immovable; decreasing it enables him to pass through solid matter, grants him flight capabilities, and allows him to levitate.
Vision's android body naturally has greater strength, speed, durability, and reflexes than a human body, as well as a self repairing system, an advanced intellect, and extremely acute senses. Vision can also fire the solar energy the jewel on his forehead absorbs either from said jewel or as heat vision. During the Heroes Return Avengers comic, Vision also gained the power of technopathy, enabling him to telepathically interface with outside technology.