The plant life and metal are fine, but the melting through all that shit....it's ok for a power but not for those posts. It needs to change per post to match rank system. For example you're a genin, right? Obviously if you cut a jonin it isn't going to melt him in 2 posts. Just not gonna happen. So say like...hmm as a genin: takes 15 posts, chunin 10 posts, jonin 7 posts, sannin 5 posts. Or something similar, that was just an example.