A Crossover Universe Of "Project Arrhythmia" And "Just Shapes And Beats: The Pink Corruption"! These Universes Collided Durring A Universal Accident Letting These Universes Meet! [The PA Universe Is Of McStarz Characters And Universe, So No Nautilus Or Anybody Else!] In This Accident A Very Familiar Nanobot Got Into A World Dubbed "The Pink Corruption"! Trying to escape Hysteria, and much is to come...

One day, a virus came along to CH 57. It spread like wildfire. Only a handful were safe. "Only one of us can win" it described...

Note: I am fully aware that this isn't how Black Heart will end, and this may become obsolete the more the series progresses and my headcanons change. Also, don't expect too many chapters. After failing to retrieve ENA's souls, Medusa is sent to Jestar. Will his creator have mercy, or will Medusa be forced to start again?

"Such a big celebration, yet I wasn't invited? What a shame, I guess I have to do this my way." -- Recently, the markers from Space and Mars have collaborated and signed up as volunteers to help build a party area for their annual anniversary celebration! Each assigned to different props - such as balloons, party poppers, confetti and lights. But within the span of 3 days, they start to notice the frequent absence and disappearance of markers, such as Purple Marker and the host, Anniversary Marker themself. Traces of evidence have been scattered throughout the whole map, each with their own individual riddles, puzzles and maps that have to be solved. Teaming up as a gang, these markers work as 'detectives' to find these pieces of evidence to find out the answer to the question: "Who or what is the cause for the missing markers?"