The Prime Superman (DC One Million) and Cythonna (The Last God of Krypton) by Gene Espy

In the Year 85,271 the Prime Superman watches from his base in the Sun as his Superman Dynasty protects the universe and beyond.

Though few know of it, he is not always alone in the Sun as sometimes the dreaded Cythonna attempts to coerce the Man of Gold as she herself cannot leave on her own power.

It used to be that her power dwarfed his by several magnitudes, though it did her little good in the end as the dreaded Kryptonian Devil God of Ice and Death is kept weakened by the Sun itself. But now that Superman has achieved a transcended energy form? She can do him no real harm.

Still. The dreaded Cythonna whispers to him, when she wishes to. He has of course learned to tune her out after the millennia. But still she tries. And sometimes Clark wonders if she knows he will break someday... But until then he keeps a watch on her. Knowing if she ever is freed she may wreak destruction and possibly eclipse even him in power.