Han Sen left the silver fox by the Beetle Knight so his doppelganger would appear more authentic; Han Sen was planning on traveling to Devil's Mountain alone.
With the angel by his side, however, he wasn't afraid. He wanted to use this opportunity to slay sacred-blood creatures and max out his sacred geno points.
He hunted many sacred-blood creatures in the sea, but because of their large size, eating a lot of them was a slow process. As a result, attempting to max out his sacred geno points this way was far too slow.
Devil's Mountain was home to many different creatures. Not long after he began ascending the mountain, he caught sight of big gorillas, with a few mutants among them.
But someone was already battling with the group of gorillas, which surprised him. He never expected he'd find someone else so bold as to hunt creatures on Devil's Mountain.