Zauber did not have anywhere to go, he would not be able to get to his home world without another of his species taking him there. Besides.... he did not want to give up on this school yet, he had friends and allies here and he would not leave their side while they still had to fight.
The search for his mage tool would have to wait, he would lead the students after the headmaster if needed.
Romans 8:31 What, then, shall we say in response to this? If God is for us, who can be against us?
1 Corinthians 13:1-3 If I speak in the tongues of men or of angels, but do not have love, I am only a resounding gong or a clanging cymbal. If I have the gift of prophecy and can fathom all mysteries and all knowledge, and if I have a faith that can move mountains, but do not have love, I am nothing. If I give all I possess to the poor and give over my body to hardship that I may boast, but do not have love, I gain nothing.