I was reading a light novel and my browser reset and I lost the title (silly me for not bookmarking it). All I remember now is mostly the beginning of the story line. Guy is taken to mountains to bond with some sort of (spirit? heavenly?) beast. There are layers of strength to this mountain, i.e. the deeper into the mountain range you get, the better the beast is. Guy has a time limit to find a beast. In the end, he risks it and gets into this diagram/formation to attempt to find his beast and miraculously finds an unknown (rare) beast from different dimension. I think this beast is lizard to dragon-like? There is a point where his beast returns to his home planet to "evolve" and the main character protects him.

EDIT: I have found it! Someone else asked about the same book in this forum. Thank you for viewing this though!