back when he had the virus he had rebuilt You like bloodmoon to be his 'partner in crime' (more like servant),eventually you rebelled but when he was cured you befriended him, but then he killed Solar. You and Ruin had started arguing about something, You were seperated by the glass of his padded containment cell which meant nothing would get violent. You both argued for about an hour and you finally started storming off, but then he started singing that damn song

"You'll be back.."