In battle, I wouldn't use this probably that often unless I came up with some sort of taijutsu strategy where the clone/ summon and I combine, then I somehow stop the movements of my opponent by maybe restraining them by locking hands with the them or something, then I could undo the technique and my summon/ partner could detach from me and attack the restrained opponent. This can be used in general along with a formulated strategy to create a surprise attack. I could be barraging my opponent with kicks, punches, flips, etc, and then I could undo this technique and have my summon/ clone join in on the attacks. That's also some ways how I could use this technique offensively. Because this is a "supplementary" classified type of technique, there isn't a direct way to counter this. To defend from the scenario which I created a few moments ago with the clone popping out and aiding in taijutsu, I could potentially combine the sharingan with the Defensive Crane technique to counter their attacks. I find this technique interesting, but to me it seems like it's uses are very limited.
In battle, I could use this technique to harden my body to do a variety of things. I could become gravel to phase through attacks, or harden my body to defend or attack. Offensively, I could use this to turn part of my body into something as hard as diamond, though I would have to be touching diamond (I believe a long time ago I read a fight where this was used in that way. I could state on my bios that they carry a small diamond around on a necklace or ring or something). This is similar to Earth Release: Fist Rock Technique, except that this requires the contact of whatever rock the user wants part of their body to become. In this way, this could be used for even more powerful punches potentially than Fist Rock Technique. To defend against the technique, I could use a raiton technique to break apart the part of their body which is rock. I find this technique somewhat useful and interesting, as it can allow the user to transform their body into many different rocks for a few different uses.
In battle, I could use this technique to harden my body to do a variety of things. I could become gravel to phase through attacks, or harden my body to defend or attack. Offensively, I could use this to turn part of my body into something as hard as diamond, though I would have to be touching diamond (I believe a long time ago I read a fight where this was used in that way. I could state on my bios that they carry a small diamond around on a necklace or ring or something). This is similar to Earth Release: Fist Rock Technique, except that this requires the contact of whatever rock the user wants part of their body to become. In this way, this could be used for even more powerful punches potentially than Fist Rock Technique. To defend against the technique, I could use a raiton technique to break apart the part of their body which is rock. I find this technique somewhat useful and interesting, as it can allow the user to transform their body into many different rocks for a few different uses.