Conversation so far:
What led to Hansen and Kiske's departures?
Guitarist Kai Hansen unexpectedly left the band in 1989 soon after the European leg of the Keeper of the Seven Keys: Part II tour.
Why did Kiske leave?
the conflicts within the rest of the band worsened, with Michael Weikath refusing to work any longer with Michael Kiske.
The decision was made to fire Kiske.
Did Hansen give a reason for leaving?
due to ill-health, conflicts within the band, troubles with Noise International, and a growing dissatisfaction with life on tour.

Question: Who replaced Hansen?
Self-contained rewrite: Who replaced Hansen in the band?