Sakaki is the devoted attendant to Kanami Ibuki, a genius painter living on Wet Crow's Feather Island. He finds himself present when a string of murders unfolds among the island's gathered geniuses.

Key changes made:
* "Serves as the attendant to" became "is the devoted attendant to" (more active, implies dedication).
* "Residing on" became "living on" (slightly more natural).
* "He is present during the series of murders that occur" became "He finds himself present when a string of murders unfolds" (more evocative phrasing and active verb).
* "Among the gathered geniuses on the island" became "among the island's gathered geniuses" (more concise and integrated).
* Removed the entire second sentence about lack of information as per instructions.