I often see Yoru as Luffy, as if he had been created by Oda, for the simple fact that he is a "Ridiculous" doll, he is a doll that requires a lot of creativity, communication, intelligence and is a lot of fun, that reminds me Luffy a lot.
I don't speak for the importance itself, but because the doll is broken, Yoru is very strong, it just requires the team to play for him and with him, if the team has the fps manual well placed and adapts well to the creativity of Yoru's player , he gets too broken