hard hitter
/ˌhɑːd ˈhɪtə/noun
1Chiefly Sport (originally Boxing ). A person capable of striking something with force.
2 Figurative. A person who or thing which is energetic, uncompromising, or direct, especially in providing unpalatable facts or strong criticism.
3 Australian and NZ informal. More fully hard-hitter hat. A bowler hat. Now chiefly historical.
Origin
Late 18th century. From hard + hitter.