Dreaming about killing a family member, especially someone who has passed away, can be quite unsettling. This type of dream often symbolizes inner conflict or unresolved feelings related to that person or family dynamics.

Killing your grandfather in the dream may represent a desire to let go of certain memories, beliefs, or traditions associated with him. It could also indicate feelings of anger, guilt, or frustration that you may not be fully aware of in your waking life. Justifying this act to your father suggests a need for approval or understanding of your emotions, while involving your brother as an accomplice might indicate that you feel a shared burden or complicity in family issues.

Consider reflecting on your current relationships with family members and any unresolved issues you may have. This dream could be prompting you to confront these feelings and find a way to heal or move forward. It might be helpful to talk to someone you trust about these emotions or to explore them further through journaling or creative expression.