Risk For A Cape
Arthur knew that any item that came from the Night Slayer would be valuable.
From his last life, he had known a bit about the Night Slayer's equipment, but there were still unknown parts. The players hadn't been able to appraise all the items that the Night Slayer had after all.
Even if the players had reached a high level, fighting the Night Slayer was still very dangerous due to the debuffs he could inflict. It was a general consensuses that it was better to avoid the Night Slayer than to engage it.
Some of the brave players had still taken the risk of appraising as many items of the Night Slayers as they could. But this was limited to the weapons he used, as well as the armor he used.
But the cape was something that had been missed.
Or rather, no one had known that the cape was actually a separate piece of equipment. The same could be said for Arthur and as such when he saw it, he knew he had to least take a look.