Lol, I got 9 students so far, I just got nothing better to do xD
Anyway, good enough.. keep in mind that like the other underground technique(any of them for that matter) you're extremely vulnerable if the opponent knows you're underground and you are likely to die if they know.
Anyhooow, next technique;
For this technique I want you to gather earth chakra and channel it through the ground and then once it reaches my clone mold the chakra in the ground beneath him. Then through manipulation cause several sharp spikes to rise up around and below my clone skewering him within the mass of spikes effectively killing him.
List atleast one advantage/disadvantage and tell me how you would use it in an actual fight