Wolfman and Kane end the split Superman saga in Action 541 (March 1983).
There is almost non-stop action in this final chapter, as Superman faces off against the merged Lord Satanis/Superman. This combined version is strong enough to hold off the real thing, but Satanis finds that he is incapable of getting the runestone energy while using one of the Superman bodies.
He splits himself from Superman, believing that the runestone will make him powerful enough to defeat the two weakening heroes.
But when the heroes touch, they begin to merge back together, and the one Satanis had controlled releases the demonic energy left behind as an astral Superman, able to turn Lord Satanis’ magic back against him.
Superman leaves Lord Satanis in his own era, defeated. The villain has a cameo in Crisis on Infinite Earths, and is rethought (and respelled) somewhat in the post-Crisis universe, appearing as Lord Satanus.
United and whole, Superman returns to the present, and finds an eager and romantic Lana Lang, hoping for a night with her new favourite man, Clark Kent.