He who defy Gods (Arifureta X OC/Male Reader)

(Season 2) Chapter 3 The Grand Gruen Volcano

Shea: I will become a cooked rabbit if this keeps up.

Tio: Hmm, personally I find this temperature quite agreeable, but... it certainly is a shame I cannot suffer the heat as you can.

Hajime: Want me to drop you in some magma? Then you can suffer too.

Everyone except Tio found the volcano's temperature suffocating. The effects of the heat were made even worse because of how stark a contrast it was from the air-conditioned car they'd been riding in so far.

Hajime: I probably shouldn't have spent all my life in Japan holed up in my air-conditioned room.

Sora: You reap what you sow. That's why next time I asked you to hang out, listen!

Hajime: Yes, boss!

Aware that the clock was ticking, the group hurried up the mountainside, complaining about the heat all the while. They reached the summit in less than an hour. At the top they found a disorganized mess of boulders strewn all about, creating a complex rock maze. The juxtaposition of jagged, glossy boulders with polished, smooth ones made it look like a rock exhibit in a science museum. Also, the sandstorm looked close enough to touch.

One boulder stood out far more than the other among the mass of stones. It had been shaped in the form of an arch, which was at least 10 meters high. As he approached it, Sora spotted a staircase heading deeper into the volcano right beneath the arch. He stopped at the top of staircase, looked back at Hajime, Yue, Aishia, Shea, and Tio, then gave each of them a confident nod.

Sora: Let's do this!

Hajime: All right!

Yue: Okay!

Aishia: Of course!

Shea: You got it!

Tio: Very well!

(Timeskip)

Hajime had thought the insides of the Great Orcus Labyrinth and the Reisen Gorge had been ridiculous, but they both paled in comparison to the absurdity of the Grand Gruen Volcano. The monsters weren't tougher or anything, but its construction was absolutely awe-inspiring. It was like nothing he'd ever seen, and what he was most surprised by was...

The sight of magma floating in the air, which filled up the whole space in front of him. It wasn't like the treetop aqueducts Hajime had seen in Verbergen. Instead, there was quite literally a river of magma floating in the air. It snaked and swerved like an actual river, making it seem like a giant red dragon was flying through the volcano.

The passageways and rooms had magma flowing here and there as well, so challengers to the labyrinth had to be wary of lava both beneath and above them.
Furthermore—

Shea: Kyaa!

Sora: Whoa, you okay?

Shea: Hawawa, thank you, Sora. I didn't think lava would spew out like that... It took me by surprise.

As Shea had said, there were spouts in the wall from which magma erupted at irregular intervals. There was no warning either, so it was hard to prepare for. Nature had provided the perfect traps for this labyrinth.

Sora(mind): Thank god I have the Sense Heat skill.

Without it, they would have had to take the labyrinth very slowly. However, what really made this labyrinth grueling was the heat, not just how hot all the surfaces were, but the atmosphere itself. Because of the abundance of magma everywhere, it felt like they were inside a superheated sauna.

Hajime: This must be what an egg feels like when it's getting cooked.

That was the most dangerous part of the Grand Gruen Volcano. Sweat poured off the party in buckets as they headed deeper into the volcano's bowels. They had to be careful to avoid drops of falling magma from above and spouts of it from the side, but they made steady progress. After some time, they arrived in a room that was clearly man-made. The room had been hollowed out by a rough tool, likely a pickaxe, and there was a glowing pink jewel slotted in one of the walls.