After killing Alman and the trio from the Aurora Clan, Arvin moved deeper into the Kalgan forest. As he moved deeper he started meeting stronger beasts from time to time. But no beast of the Kalgan posed any threat to Arvin. He was after all strongest being on the 1st floor right now. With that, he moved deeper into the forest.
Arvin eventually met the Fierce bird, the strongest beast of the 1st floor. Arvin remembered that when he came to Yggdrasil this fierce bird was the first beast that he saw. Arvin was scared shitl*ss when he saw that bird. The sheer size of the bird was enough for him to sh*t in his pants. But then he was a weak boy with no strength at all. From then he had come a long way. Now when Arvin came face to face with that bird, all Arvin could think about was the sheer size of the drumstick that could be made from this bird's legs.
