One possibility of a sentence that includes phrases, clauses and parallel structures could be:
Aina and his friends reported Wenli to the school authorities, who took over the students' class after Miao was sent to be reformed in the country.
Another possibility may be:
Aina and his friends reported Wenli to the school authorities. And after Miao was sent to be reformed in the country, Wenli took over the students' class.