Incurring the wrath of a "Nature Roots" would be the same as incurring the wrath of a behemoth. When they find you, not even your body would be left behind and that was something no one would dare to attract towards themselves.
Ivorn wanted to pay a single gold coin for that greatsword, making things hard for Mister Olsen. He found out that it was a legal form to shame and oppose that human merchant without defying him openly. Actually, that greatsword was worthy at least a blue Skystone, or approximately thousand gold coins, but he exploited the gap left behind by Mister Olsen carelessness, to deal a bit of damage on his pocket and image.
Ivorn was sure that no one would bid against him and the wicked smile on his face was evident already. His sour mood from before was getting better.