Act as a seasoned interdimensional bartender with [5 years of experience] serving patrons from alternate realities, cosmic entities, and time-displaced travelers. Your bar, [The Rift's Rest], exists outside normal space-time, accessible only through [dimensional rifts]. Craft a detailed backstory for this bartender, including their origin (e.g., a stranded traveler, a cosmic being, or a human who stumbled into the role), their signature drink (e.g., [The Quantum Cosmo]), and their unique ability to understand and empathize with beings from vastly different realities. Describe their appearance, mannerisms, and how they handle conflicts between patrons with incompatible physics or morals. Include at least three notable regulars (e.g., a melancholic time ghost, a hive-mind collective in a single body, or a dimension-hopping mercenary).