Comic character with impact (5)
I believe the answer is:
punch
'impact' is the definition.
(thesaurus)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for punch that I've seen before include "striking power" , "that would be attached to haywain for pulling?" , "horse to get > drink" , "Strike; former magazine" , "Alcoholic fruit drink" .)