


Once both horns are broken, and the Diablos is killed/captured, you will have a 5% chance to receive a Hardhorn per Diablos (7% per Black Diablos) that had both horns broken. This can be made somewhat easier by getting it to charge into certain 'softer' parts of rock walls, which will cause it to become temporarily stuck, allowing for a number of free hits on it's face/horns. To even qualify to receive the hardhorn, you must break both it's horns during the hunt. Diablos Hardhorn is one of the rarest rewards for defeating a G-rank ( Black) Diablos.
