caeru could solve the kira case both by figuring out the mechanics of the death note and tracing it back to light yagami but his real strength comes from not having any one fucking legal name to write in the book because every single one of his aliases is both true and false at the same time. lark on the other hand would not figure out how the the death note works but would somehow uncover kira anyway through an ace attorney esque series of loopholes, tomfoolery, and somehow getting ryuk to testify on the stand