What happens to the old universes that the players leave behind? I mean i know the planet is destroyed but the condesce was still in the unverse 600 years after Sgrub started

It keeps going until the Universe dies. For the Red Universe, that’s 413 years after SBURB, and for the Blue Universe, that’s 612 years, but arguably if the Session happens early on and there’s no weird anomalies like. First Guardian Fuckery and Cancer, the Universe could potentially last several million more years.