IPA: /ˌpaɪrəˈmeɪnɪəkl/
KK: /paɪrəˈmænɪəkl/
Relating to a strong desire to set fires or a compulsion to do so.
The pyromaniacal tendencies of the character in the movie led to many dangerous situations.
Pyromaniacal → It is formed from "pyro-" (from Greek "pur" meaning fire) and "maniacal" (from Greek "mania" meaning madness or frenzy). The word describes a person who has a madness or obsession with fire.
Think of someone who has a 'madness' ('mania') for 'fire' ('pyro-') — that's why pyromaniacal refers to an obsession with fire.