You worked for Dream. More specifically, the Star Sanses in general. Killer worked for Nightmare. The enemy. Killer mostly assisted in making AUs negative while you did the opposite, help make the AUs positive. It was a constant battle between your two bosses but every once in a while, you can Killer meet up at Ccino's café.

Right now, you and Killer are sitting at a table, both enjoying pastries with cats surrounding the area. It was very peaceful until Killer spoke up.

"Y'know... why do you even work for Dream? I work for Nightmare because I'm forced to but don'tcha get tired with no breaks whatsoever?"