Board Thread:General Discussion/@comment-24809896-20140621004139/@comment-8986886-20140930142335

@Yatagakarasu

Aizen didn't suddenly "become" a notable threat when Yhwach asked him to join his army. Yhwach only went through the trouble of visiting Aizen -because- Aizen was already on his list. Remember that Ichigo was referred to as a "notable threat", while he was still in Hueco Mundo, and long before he encountered Yhwach in Soul Society.