Conversation so far:
What was giant killer and why was Rey Mysterio called that?
Rey Mysterio became a giant killer by defeating large opponents such as Kevin Nash, Bam Bam Bigelow, and Scott Norton.
when was Rey Mysterio's unmasking?
In 1999, Rey Mysterio lost a Hair vs. Mask match, forcing Mysterio to remove his mask.
what happened after Rey Mysterio's unmasking?
Rey Mysterio publicly expressed his disappointment over being unmasked.
did Rey Mysterio win any titles?
In July at Bash at the Beach, Rey Mysterio defeated Psicosis to earn another opportunity at the Cruiserweight title. The next night, he defeated Malenko to win his first Cruiserweight Championship.
did Rey Mysterio set any records?
On the June 17 episode of SmackDown!, rey Mysterio defeated Chavo Classic for a record-setting third Cruiserweight Championship reign.
did Rey Mysterio do anything else that gained him fame, besides his Cruiserweight Championship?
In WCW, Rey Mysterio helped popularize the high-flying lucha libre wrestling style.
did Rey Mysterio have any conflicts?
The match at WrestleMania was part of a storyline in which Ray Guerrero turned on Mysterio and beat him up. Guerrero and Mysterio continued to feud.
was Rey Mysterio ever injured?
On the October 18 episode of Nitro, Rey Mysterio and Konnan teamed up together to defeat Harlem Heat. Mysterio, however, was injured during the match.
did Rey Mysterio's career end after his injury?
Rey Mysterio returned in early 2000 and remained a steady performer.

Question: was his unmasking popular?
Self-contained rewrite: was Rey Mysterio's unmasking popular?