This is a video on Loki's aggression. Not all imprints will behave this way, but this behavior is very common in male birds which leads to people not understanding them and these birds getting abandoned.

Sometimes especially with rescues or abandoned squabs its impossible to not have the bird imprint on you. You can help avoid behavior issues by having your pigeon socialize with pigeons in a loft during its fledging time.

Sorry if i rambled a bit i had a long day haha