The Between is not a safe place for people made of physical matter. Most people... die pretty quickly on exposure. Luckily for Lantry this particular bit isn't empty and he's bundled up by something that isn't quite a world... yet.
The being wakes for the first time in response to this stimulus. It stretches part of itself through the hole and into the world it came from drinking in knowledge and building an understanding of how things are.
It samples the flood of knowledge. It's a delight, absorbing knowledge and... passing it on. That will be its purpose.
It will also need a name. Learning. For the moment, Learning is their name. The meaning... not a word in a particular language.
With that decided they start reshaping themself. Sturdy stone halls and shelves filled with books and scrolls. Carefully crafted labels written in raw meaning. Desks and chairs of the finest craftsmanship.
That's enough to be getting started with. They carefully deposit their catch into one such chair and allow them to wakeup.