The young man's glowing eyes weren't just some sort of decoration. It is an indication that his Mystic Eye has activated and from the looks of it, these eyes were capable of unlocking the door or perhaps removing the Formation Art on it!
They didn't question the young man as they allowed him to work on it. They don't want to empty their mana reserves after all. They haven't completely escaped yet and preserving every bit of their strength is necessary.
"I need some time to open this up… The mana formation is too complicated. It will burn me alive if I made a mistake. I need 15 minutes… No, maybe 10 minutes… Should we find another way?" The young man said as he looked at the people gathering behind him.
He then noticed Ceri shaking her head.
"All the other doors are most likely similar to this. There's no point in going elsewhere. Ten or fifteen minutes should be just fine. We'll just try to recover our mana in the meantime."