Helloween are a German power metal band founded in 1984 in Hamburg, Northern Germany by members of bands Iron Fist and Gentry. Its first line-up consisted of singer and rhythm guitarist Kai Hansen, bass guitarist Markus Grosskopf, lead guitarist Michael Weikath, and drummer Ingo Schwichtenberg. After the release of a self-titled EP and their debut album Walls of Jericho in 1985, it expanded into a quintet with the addition of singer Michael Kiske, Hansen choosing to focus on guitar instead. Under this line-up, they released the Keeper of the Seven Keys albums (1987 and 1988), which established Helloween as a notable heavy metal band and led to the creation of the power metal subgenre.

The year 2000 saw the release of The Dark Ride, a more experimental and darker album than their previous releases. It came complete with downtuned guitars and a gruffer singing style from Deris. Immediately following the tour, Helloween parted ways with guitarist Roland Grapow and drummer Uli Kusch. One version of events states that Weikath, Deris, and Grosskopf felt that Kusch and Grapow, in particular, were spending more time on and paying more attention to their new side-project, Masterplan (Grapow's output on Helloween albums had dropped to barely one song per album by that point); since the others believed that Kusch and Grapow were not one hundred percent dedicated to Helloween, they were dismissed.  They were replaced by guitarist Sascha Gerstner (ex-Freedom Call, Neumond) and drummer Mark Cross (ex-Metalium, Kingdom Come, At Vance, Firewind), culminating with the recording of another studio album, titled Rabbit Don't Come Easy, in 2003. The band met Sascha via a recommendation by producer Charlie Bauerfeind. According to Grosskopf, one day he was recording something with Freedom Call "and later on we called him up and he went to first meet Weiki because it was very important that Weiki finds a player that he can play with and also communicate and understand. [...] So we got him on the island where we recorded and let him hang out with us a little and then he decided 'Good, let's go'." Later in 2012, on an interview with Metal Shock Finland's Chief Editor, Mohsen Fayyazi, Roland stated:  Cross could not finish the album due to mononucleosis, completing only two tracks; the drum tracks were completed by Motorhead's Mikkey Dee. Stefan Schwarzmann, former drummer of Running Wild and Accept would shortly thereafter take over the drumming duties. Despite a somewhat tepid response to the album, Helloween nonetheless completed a successful world tour, highlighted by the return of classic songs such as "Starlight", "Murderer", "Keeper of the Seven Keys" and "How Many Tears" to the setlist. Additionally, the band toured the United States for the first time since 1989, playing to sold-out crowds at nearly every venue.

Answer the following question by taking a quote from the article: Who were they replaced with?
guitarist Sascha Gerstner (ex-Freedom Call, Neumond) and drummer Mark Cross (ex-Metalium, Kingdom Come, At Vance, Firewind),