[x] No, they can probably just wrap themselves in robes and do as best they can.
[X] Modify the entryway so that its protected from water pouring in it with a small roof and then modify the tunnel so that its the lowest point, causing it to be an cold air trap yet allowing fresh air to come in. Last modify the rock room with dirt and whatever soft material is around to raise the sleeping area a few more inches so that they are above the colder air. Wrap themselves in cloned robes. One person stays awake in watches.
[X] Modify the entryway so that its protected from water pouring in it with a small roof and then modify the tunnel so that its the lowest point, causing it to be an cold air trap yet allowing fresh air to come in. Last modify the rock room with dirt and whatever soft material is around to raise the sleeping area a few more inches so that they are above the colder air. Wrap themselves in cloned robes. One person stays awake in watches.
In the end, Ernie was sadly outvoted - there would be no fire that night, nor would the entrance be blocked off, meaning that if it began to pour, things could get uncomfortable. Still, he cooperated, as overt resistance was futile when it came to dealing with such matters, even if he privately was annoyed that he couldn't do much of the necessary alterations she requested with his wand.
Oh, perhaps if the people with Selina were her brother and his jolly band of adventurers, whose exploits in Faerun were nothing short of legend, then this would be trivial - a master of transfiguration would have had very little difficulty doing everything she asked, much less a party. But then, neither he or Matou were nearly at that level - or at her level, for that matter - something he thought that Selina forgot sometimes.
'She expects too much of people, I think.'
It made him want to be more than he was, to be someone worthy of her - even if he knew that right now, he wasn't anywhere near worthy.
That was why he'd suggested just blocking the entrance - that was something he could do, as opposed to raising the sleeping area, modifying the tunnel crawl-space, and building a roof for the entryway - things that he knew, knew, would take more time than any of them had.
Still, she'd insisted otherwise, so all he could do was try...
...only to be proven right, given how, as he was scooping up dirt in his hands, there was a sound as if the sky itself was tearing itself open, and with it, a deluge began.
Only it wasn't just rain that fell, but great nodules of ice bigger than his fist, violently crashing into the ground.
"Guh!"
One moment he'd dumped the load of dirt and twigs he'd collected and was running for the rock.
The next--
"Huh? Why am I...?" He was on the ground, looking up at the--
A flash of white, then another, as stars blossomed in his vision.
"I...I..."
Whatever he was about to do next, it didn't matter, as a hailstone the size of a softball smashed into his unprotected face.
Ernie is dead, with Shinji and Selina having been lucky enough to take cover just before the storm hit. The water contraption was set up in the covered tunnel, using duplicated robes. Still, they are somewhat wet and the temperature is dropping precipitously - the boy is shivering.
What should Shinji do?
[ ] Start a fire - warmth is the priority, and the rock shields them from sight. Mostly
[ ] Suggest that they strip off their wet clothes and huddle together for warmth while wrapping themselves in copied robes
[ ] Wrap Selina up in robes and endure the cold stoically - someone needs to stay on watch, since Ernie...
[ ] Suggest going down into the burrow, if its not flooded
[ ] (write-in)