In the eyes of the Illume-union, Sheyan was like an omnipresent specter, always appearing where he needed to. For example, for those fighting at the front had several times where they were about to suffer an attack, but Sheyan had showed up in the nick of time; either through his fists, or the repelling ability of the shotgun to repel viperwolves away, and thus obstruct the viperwolves' onslaught.
Speaking from the party's perspective, Sheyan's readiness to get attacked by these beasts, was obviously more advantageous than having the beasts attack Sable. That was because the latter would have a higher chance of suffering from an explosive strike. Besides, it was naturally more worthwhile for the prepared Seaman, who obviously had excellent defensive strength, to get bitten instead of their own contestants who weren't prepared.