Naraku has taken out a mountain and forest just by being near it. He's even turned a river into a pool of miasma. Aizen and Ichigo would be luck to get close. A big hill/small mountain busting attack is compared to a freebie breeze to his durbility.
Sorry man the attack is called Bakusaiga which you can do your own research on. I'm not stating anything I can't prove it's right in the manga near the end. I know every character here and can defend them all on different levels. So you can take my word, watch the anime (to get a general idea),or you can go and look in the manga.
Also what do you want to see?