"Need material for that."

"Are we near the workshops?"

"Not close enough that we could get back without giving something the chance to come up."

" - Can you tell Xunyu to bring something?"

"Yes. What do you need?"

She eyes the hole. "Think we can use the phase-control spell..." She's done enough maintenance shifts to have an idea of what actual materials to specify, too - and what equipment. 

Then Chengsu will pass that information along.

In the meantime... there's some things that need discouraging from climbing up.

One way or another. 

Chengsu activates her communication stud. "Xunyu?"

"Chengsu? What's up?"

"I was attacked. Along with Luthien and El. A group of seniors dragged us down near the graduation hall. There's a hole in the wall we need to fix."

"Shit - into the graduation hall?"

"Not directly. We're a ways up still. But it's a direct path."

"I'm bringing backup. What do we need to bring?"

She lists off Luthien's requirements. "...And my spare clothes. If possible."

" - Will do."

"The breach is contained for now, but- sooner would be better. Thank you, Xunyu."

"I'm on my way, Chengsu." And she turns her full focus to arranging the promised backup - and keeping Chengsu updated on ETA as she works. 

Which at least gives the defenders a good idea of how long they need to ration their efforts for. 

Chensu will donate mana to keep them going.

It helps, a lot. 

(They've probably put a big dent in Shanghai's mana stores, between this and the mawmouth. She decides not to think too much about that. Not now.)

Better that than let the graduation hall flood into the school, El thinks they'd agree.

Shanghai seems to agree - the first backup to reach them is one of the seniors, Li Jiana's twin Jiaxiang, with his own small crowd of hangers-on carrying some of the supplies Luthien requested - and bringing with them a few grim-looking maintenance track kids with their own supplies.

Jiaxiang is, apparently, an artificer - he immediately starts helping the maintenance track kids set up temporary barriers to delay the hoard trying to squeeze its way through the hole.

- And most of those kids aren't seniors, the sisters might notice. Most are juniors. A few sophomores. People with skin in the longer game.

- Including exactly one freshman, who's apparently mostly along as an additional body to carry things and obey orders, though it's clear she has a good sense of the maintenance of these stairwells too.