The first jutsu is pretty cool, it has its limitations but it could prove an asset to the right person at the right time. For example, Hayabusa cannot be sensed beyond the five senses, and can eliminate themselves from existence. This jutsu nearly mocks that ability from the opponents POV, so using it in that way could have some cool effects. If you aren't a Hayabusa though, you are going to get caught considering everyone has some sort of sensing, like you said. It could be used with Tai, but without Y/Y, that would be it.
The first time I remember seeing this was when Goku used it against Master Roshi in the World Tournament in Dragonball, and that experience in itself taught me all that I need to know about this technique lol. Basically through use of the clone technique and rapid movement, one creates images of themselves that linger for a bit, masking the users movements until the next copy can be made. Like the above technique though, sensing is the downfall here. Even though most people would trust their eyes, they would claim that their character would trust their senses and find the real you.
