His trademark was the usage of Puerto Rican slang terms, such as Corrió como alma que lleva al Diablo (The person ran like a soul possessed by the Devil).
Another one of his stories began with "A well-aimed stab to the heart..."[4] His writing style earned him awards, but also criticism.
In response, in 2003 Mangual became party to a lawsuit that said Puerto Rico's criminal libel laws were against Freedom of the Press.
The lawsuit resulted in the criminal libel laws of Puerto Rico being struck down for being unconstitutional.
[5][6][7] Mangual died in Mayaguez and is interred at the Las Mercedes Cemetery in Ponce, Puerto Rico.