Tā de wàngwéi zuìzhōng hài le zìjǐ, yě liánlei le jiārén.
His reckless behavior ended up ruining him and dragging his family down with him.
Tips
usage
妄为 lives mostly inside four-character idioms, all of them condemning: 胆大妄为 (brazenly reckless), 肆意妄为 and 恣意妄为 (doing whatever one likes). 妄 is 'wild, absurd', as in 妄想 (wild fantasy) and 狂妄 (arrogant); 为 is wéi 'to act', not wèi.
