Steel Body

Upon throwing ourselves into it, the Beastmuth quickly responded to our hostility and mightily swung its right front limb, shooting its hard, purple scales at us. Seeing those projectiles, we immediately swayed our bodies several times to gracefully avoid each of the scales. 

With bodies enhanced by Level 10 spells, we were able to get close to it in an instant. Holding the grip of our own swords, we slashed our naked blades, intending to cut the Beastmuth's muscular front limbs.

Cling! 

However, instead of a flesh-cutting noise, a screeching metallic collision rang out. The monster had activated its Body of Steel extra skill, which insanely made its scales tougher. So tough that our swords were only able to cut an inch through it and did not go through its flesh. 

"What the heck?!" Sister was flabbergasted when we stopped dashing several dozens of meters from the Beastmuth. "Our swords did not make it through!"