"'Shit-all' is actually a pretty good description of what we've got," Rin says with a frown. He's surrounded the teleporter in a wall of blue flames, but judging by his cold sweat, it's a lot harder than it looks. Between the Mother of Invention barring his powers and the lack of his sword, he's really running on fumes.

Thankfully, Satanic fumes are stronger than most. 

"Are there any... like, pieces of furniture in the staff rooms?" Maybe they could use those to block the hallways...