Red Sun Radiation: Natural in Krypton's planetary system, red solar radiation replaces the higher-yield yellow solar energy in Superman's cells, robbing him of the fuel for his powers. (Pre-Crisis, red solar radiation was said to lack the superpower-enabling "ultra solar rays" that yellow solar radiation contains.) This process does not have the painful, ...
There are both Kryptonians and a "New Krypton" on Prime Earth.
There are a few Kryptonians (I count 14) that have made appearances, including:
Kara Zor-El (also duh!)
General Zod (Dru-Zod)
Others: Jonathan Lane Kent, Rao, Xa-Du, Lor-Zod, Faora Hu-Ul, Lar-On, Jan-Al, Kon.
Revealed after the ...