Simplify the following text for a Grade 7 native English-speaking person.
Original: The feud first started on the March 7 edition of Raw when Orton challenged The Undertaker to a match at WrestleMania billed as `` Legend vs. Legend Killer '' .
Simplified: The feud first started on the March 7 edition of Raw when Orton challenged Undertaker to a match at WrestleMania billed as `` Legend vs. Legend Killer '' match .