Because sometimes, one ending's requisite exclude another ending. So, make sure the path you take is the one that goals your wished ending. I'll try to keep a note on that as the guide goes on, but pay attention! Sometimes, one tiny mistake can close a door later! It's because this ending demands a focused strategy, and the other part of the guide will not help you that much. Just for the records, this bug remains at the version 5. Thanks to this, the strategy options grow a bit thin, specially for the Intelligent type, which could use some dates at the Blue Mountain with Ami.
