In s02e46 Dio's World, Part 2 when, Dio mortally wounds Kakyoin and Kakyoin realizes his stand's power, why did he use Emerald Splash, knowing that the effort would immediately kill him? Granted he was mortally wounded, yeah, he didn't have much to lose, but wouldn't it be easier to simply communicate to Joseph via their stands?
It would a) obviously be less cryptic and b) require even less effort, because they seem to have been communicating through stands during battles and also wounded.
Therefore, why did he not explicitly tell Joseph about Dio's power and instead used Emerald Splash to crush the clock?