What is the purpose of a counterargument in a persuasive text?

The verb in the sentence is in what voice

In part one of "cruel tribute," how do king aegeus's actions affect the advancement of the plot? he causes ariadne to fall in love with theseus. he causes theseus to become the new king. he causes the birth of a hero in troezen. he causes king minos to become angry.

Brutus: but as he was ambitious, i slew him. . who is here so base that would be a bondman? if any, speak, for him have i offended. who is here so rude that would not be a roman? if any, speak, for him have i offended. who is here so vile that will not love his country? if any, speak, for him have i offended. i pause for a reply. which rhetorical device does brutus use in this excerpt?