Zach can slightly understand the essence of this problem. He didn't say anything else when Bell Avalon said again, "I've asked Mr. Lopez to invite you on his team. That's for you to gain experience about shadow beings. You will join them to purify the essence of the matter."
"Don't worry, this won't affect your job as Gatekeeper. They will start moving tomorrow night." Right after Bell Avalon said this, Zach raised his eyes then asked, "Why postpone until tomorrow?"
Bell Avalon didn't make any additional moves, he looked the other way, "They need to find out more information"
Zach nodded in agreement, basically he wasn't that scared of this. Instead he thought that this was a good opportunity to see how the real Guardians acted. Putting aside the fact that he had basically encountered some shadowy beasts.
After a moment of silence and contemplation, Zach straightened his eyes again, "Mr Avalon, you're asking about my purpose here..."