The Entertainment Weekly article identifies one of the dead heroes on Earth 90 as Vibe. Or more accurately a version of Vibe. If true it is hard to say how many of these characters are native to Earth 90. Vibe could have breached some of them from other Earths to help fight the Monitor. Unrelated to this but worth sharing. Here is a picture John Wesley Shipp shared of him and Sam Jones, Flash Gordon. From a convention yesterday.