The space is not too big, but Noah feels that this is just the entrance, and there will definitely be a bigger space inside.
But after careful consideration, Noah decided to temporarily give up exploring the space underneath, and bringing the wounded back first was the most important thing. Anyway, there will be time for him to explore slowly after he is sent back.
After making the decision, Noah first threw the soil back to its original position, then dug some more to fill it, and finally used the guardian ability to strengthen the layer of soil.
This is also to make a mark so that he can find this place when he come back later.
This was something Noah discovered accidentally when he and Charlotte were studying ability before, but because the effect of battle was not very good, he never used it.
After Noah was done with it, he used his devil claws again to lift himself up.
The vision gradually turned from darkness to clarity again.