.

Mignola also did two nice single issues of SUPERMAN during the later part of Byrne's run.

SUPERMAN 18 (June 1988) , scripted by Byrne, with Mignola/Kesel art.
https://readcomiconline.li/Comic/Superman-1987/Issue-18?id=16628

and SUPERMAN 23 (Nov 1988), scripted by Roger Stern, with Mignola/Russell art. The issue after Byrne left the series.
https://readcomiconline.li/Comic/Superman-1987/Issue-23?id=16681