Hoseki

Hoseki was the younger brother of Keseki.

He was killed by Ryun when one of his friends tells him to violently shack the tree Ryun was sitting on.

Trivia:

 * This makes him the first decribed death in the series.
 * Though not described in the series: but he was a large bulky male and had the strength of three elephants. It's unknown how Ryun was able to kill him.