Last September, some designs for KISS were stumbled upon. By process of elimination, most people assumed the one episode we did not have a full description for was the KISS episode. However, it appears the KISS episode has been scrapped, as "The Legend of the Gold Microphone!" description was just revealed and it doesn't mention Gene Simmons at all, but rather Joseph Simmons aka Reverend Run from Run DMC. Given all the other guest stars have been announced, the KISS episode must have been scrapped for some reason. Here's the full description of this episode from Foxtel AU:
Our mystery teens work with Joseph "Run" Simmons (aka Reverend Run) originally of Run DMC to get to the bottom of the mystery of the ghost of a famous bandleader from the 1930s haunting a hip-hop youth center in Harlem.