Talk:Light Novel Volume 10/@comment-49.149.17.228-20150503121724/@comment-94.175.151.35-20150503181446

there's ten waves total, the spirit turtle appears on the 7th but that's because the three idiots unbound it and caused the 4th-6th waves to be skipped over completely, and they aren't directly related to the otherworldly heroes, it just seems that Glass can use the wave to cross worlds while it's happening and the book hero might also be connected, since he appeared immediately after the spirit turtle incident in the LN.

To clarify, Larkberg's lot showed up when there was no wave, and Naofumi got into Glass' world and back without a wave being present, so it is possible to use the wave to cross worlds but that does not appear to be the only way.