Sasori kept his eyes focused on his sensei as he stared with a grin on his face at Sasori’s puppet. Sasori frowned at his sensei, seeing a puppet modeled after him must’ve made his sensei feel special. The puppeteer formally from the village of Sunagakure listened to the third kazekage as he spoke, stating that he would train Sasori in the arts of iron sand. Sasori couldn't help but let out a smile. Learning Iron Sand would open up new paths for him to use with his puppet of the third and become a deadlier foe to face in battle.
Not taking his eyes off of the third, Sasori watched his sensei stand up from the near bonfire and flick his wrist. Sasori then noticed what would appear to be of ball of iron sand emerging from the ground in front of the third. “Amazing” Sasori mumbled to himself as his sensei caught the ball and displayed it to him. As the third threw the ball towards it, Sasori then held out his right hand in attempt to catch the ball made of iron sand only to witness it crumble in mid-air which resulted in grains of sand falling into the eyes and mouth of Sasori.
I am a puppet too ya know, that's dangerous! Well, so much for a game of catch.
After shaking his head to do away with the grains, Sasori looked puzzled as his sensei broke into a laughter after the ball crumbled onto him. He didn’t see what was so funny, but he didn’t let his sensei teasing him with a game of catch distract him from his goal of learning. The third then proceeded to question Sasori on his knowledge of the technique and of Iron Sand.
What you just did seems to be a technique where the user is capable of molding iron sand from a nearby source to his heart’s desire but preferably a tool to be used for offense or defensive maneuvers. I would say that the many possibilities that the technique brings is a strong point and I didn’t notice you weaving together any hand seals which gives me the assumption that none are needed, but then again you are a master of performing techniques like this. Weakness wise, the formation of the tool being formed by the iron sand may give the opponent time to react. Also I don't see an attack such as this, doing fatal damage if used incorrectly.
As far as Iron Sand in general goes, it is neutral to all of the basic elements, which excludes ration. Because Iron sand techniques are essentially manipulated by magnetic forces, ration has the capabilities of disrupting these magnetic fields and thus disrupting iron sand techniques. Seeming that Iron Sand is neutral to the other basic four natures of chakra, a technique of the same rank or above would have to be put to use in order to potentially disrupt the direction of iron sand techniques if there was a clash of elements but due to the weight of iron sand and the magnetic field, this may not always be the case.
After he finished speaking, Sasori starred at his sensei who had once again got comfortable by the bonfire. He starred at the man, waiting for his response to Sasori’s knowledge of Iron Sand.