Origin: Singlish – This is a misspelling/pun of the word powerful.
Powderful is often used as a pun to sarcastically praise someone of his/her qualities.
Ah Seng: “Ah Beng ah, your english is sibeh powderful sia. I witnessed your conversation with the ang moh when you were trying to sell her perfume. You used phrases like “a person of your elegance and class” lah, “befitting your simi status” lah blah blah lah…pui…..