set on
https://gyazo.com/67014fd7f7aa973c8c1b076070adbcf0
source: The Simpsons Gifs
set on (or set upon)
attack (someone) violently:
⦅かたく⦆ Aを襲う(attack) (!しばしば受け身で)
e.g. he and his friends were set upon by a gang.
#phrasal_verb