Conversation so far:
What was giant killer?
Mysterio later became a "giant killer" by defeating large opponents such as Kevin Nash, Bam Bam Bigelow, and Scott Norton.
when was his unmasking?
In 1999, after the two factions of nWo reformed, they demanded that the LWO disband.
what happened after that?
Mysterio later became a "giant killer" by defeating large opponents such as Kevin Nash, Bam Bam Bigelow, and Scott Norton.
did he win any titles?
he defeated Billy Kidman to win his fifth Cruiserweight Championship.
did he set any records?
Mysterio and Kidman lost the World Tag Team titles to Raven and Perry Saturn in a Triangle match.
did he do anything else that gained him fame?
Mysterio and Kidman teamed with each other and defeated Flair's Four Horsemen stablemates Chris Benoit and Dean Malenko to win the WCW World Tag.
did he have any conflicts?
The match ended with a disqualification win for Flair, even though Arn Anderson's interference on Flair's behalf should have theoretically disqualified Flair.
was he ever injured?
CANNOTANSWER.
did his career end?
CANNOTANSWER.

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