I want to know the answer to the following question:
Who are enlightened people who vow to continue being reborn?
All the background I'm provided with is that "Mahayana also differs from Theravada in its concept of śūnyatā (that ultimately nothing has existence), and in its belief in bodhisattvas (enlightened people who vow to continue being reborn until all beings can be enlightened).". Is that enough to answer the question?
Answer: yes