In the movie we saw today, conch shells are used to make horns and perform the symbolic "ahn" sound during serious ceremonies. People believe the sound has the power to excess evil. Conch shell horns are the income of Yamabushi. It is generally believed by Japanese that Yamabushi can gain power by doing shugendo on the mountain for 4 months. There are articles in other countries showing that the people go through tough environment on purpose will obtain mystery power. These are probably made by people living in uncontrollable cruel environment to comfort themselves. Therefore all the unexplainable suffer they had will be the source of their inner power. At the end, the Yamabushi said that doing everything by himself is originally part of Shugendo procedure, which kind corresponding to the self-conforting theoery.