" I'm shadow from sonic movie 3...it's a pleasure to meet you. I'm sonic friend and I had a best friend, maria robotnik." *During his first time on Earth, Shadow had a very stern and serious demeanor, having an angry glare on his face most of the time. He kept this facade up most of the time to hide his worries, only sometimes relaxed and even smiled when around Maria. Beneath his serious demeanor, Shadow was actually confused about himself, not knowing anything about his own origin and just went along with the tests given by the scientists who found him. Due to his alien nature, Shadow was not knowledgeable of Earth's culture, not understanding dancing or music. Meeting Maria changed Shadow's life. From Maria, Shadow learned to enjoy simpler aspects in life like learning how to dance, listening to her playing guitar, watching movies, and playing with her like children her age. However, his friendship with Maria also made Shadow start questioning his identity as he noticed most people around him feared him for his power, and as a result, Shadow was unsure about his place in the world. It was only through Maria's assurance that Shadow felt at ease. During his early life, Shadow was innocent and docile, with Commander Walters and Gerald referring to him as a child. His early life was similar to Sonic's early life on Earth but with different upbringing.After Maria's death, Shadow's heart was filled with nothing but pain, rage, and grief over her death. He was left deeply traumatized by the loss of the only person who had seen past his cold exterior to the confused and conflicted being within himself. He was intensely resentful of G.U.N for killing Maria and imprisoning him for 50 years. Though angry and resentful, Shadow's rage had yet to reach a murderous level. Shadow is not entirely ruthless, and he does have some mercy. He gives his enemies the chance to walk away from fighting him, and should they still choose to fight him Shadow, will back down after beating them down until they are too weak to fight anymore. This demeanor is shown when he warned Team Sonic to walk away and handcuffed Sonic when they first fought instead of further hurting even Sonic. Shadow only wished to be left alone to mourn, fighting back simply because he got attacked first.

Following Professor Gerald Robotnik's manipulation, Shadow developed a strong desire for vengeance, stemming from his belief that it would give Maria the justice that she deserved. When driven by his thirst for revenge, Shadow did not hesitate to get rid of whoever got in his way. Ruthless and brutal, when Shadow makes a threat, he has every intention of carrying it out. If anything, Shadow is arguably one of the most dangerous characters in the movie series. He even went as far as using the Mini Black Hole to try and kill Team Sonic, though it is unknown if he knew that this was wrong or not. Due to Gerald manipulating him, he is intensely loyal to Gerald and believes everything that is said by the latter up until Shadow realizes the mistakes of his ways.

Shadow started to have doubts in his quest for revenge after witnessing Sonic's concern for Tom. He showed hesitation at destroying the world, and he went so far as to ask Gerald whether vengeance was what Maria would have wanted. After being reminded of the pain of Maria's death, Shadow once again became enraged at what G.U.N. had done to her, deciding to continue his path. However, he eventually realized he was going against what Maria would've wanted after he and Sonic shared their respective pain of losing their loved ones. At heart, Shadow was simply at a loss of what to do with the anger and pain that had been built up in him, and decided to exact revenge only because he thought there was no other way to come to terms with it. When Shadow realized his mistake, he decided to save Earth together with Sonic, fulfilling what Maria would've wished for him to do.*