Endurance Challenge 

A few more months had passed, and the pair had made their way all the way to the place that the map they had conquered earlier led them to.

Unlike the crystal they had found earlier—which they still cultivated with it occasionally—this place they had arrived at a few days ago didn't have a special resource that could be taken.

What was available in the area was an opportunity that could only be seized there. 

That's why, after Minos and Forfex's first few days since arriving there, they were still in this area, both amid a test of endurance.

...

In an area where magma covered an enormous terrain, which seemed to have no limits, as if it were a scorching red sea, Minos and Forfex were in the middle of a small black island surrounded by the sea of magma.

The two of them were bound by huge chains, their arms and legs stretched out, while with each passing day, the level of the magma got closer to where they were.