Flying fish
Third. So this spinel relates to time and space...so it would make sense how it accompanied mc when the latter got reincarnated...but it doesn't tell us that the possessor of the spinel can reincarnate.. if it did that monk who owned the spinel before mc would have continuously used it and reincarnated many times to lead an unperishable life... So my guess is MC's lover chi yao did something to ensure mc reincarnates.