This dream may symbolize unresolved feelings and conflicts with your ex-partner, Liam. The Roblox game represents a virtual world where you can escape from reality and confront your emotions in a safe space. Joining a server with Liam’s main and alt accounts may suggest that you are still connected to him in some way, even though you may not be in contact in real life. The system in the game that you couldn’t access may represent your difficulty in communicating with Liam in the past. Your avatar being a murderer in the game may reflect your feelings of guilt or anger towards Liam. The fact that you were the last murderer left and needed to kill two people may symbolize your desire to get revenge or closure in the relationship. Giving your dog a birthday card meant for your sister may represent your attempt to distract yourself from these intense emotions. Overall, this dream may be a reflection of your subconscious desire to reconcile with Liam and resolve any lingering conflicts.