I wrote a very long theory in Reddit, I'm reposting it from there since it's too long to post here.
https://www.reddit.com/r/twentyonepilots/comments/1kv9tdn/the_line_is_blurring_theory_part_1/
TLDR; Clancy is a character that Tyler created to be his own counterpart in a lore setting, and he wishes to eventually burn it all down, put it all on Clancy and destroy him to finally free his mind. The line between our reality and the lore has been constantly blurring album by album, and Breach will have the clearest songs up to date. (We will have songs that will easily connect to real life issues Tyler had, and while we might have music videos about the lore, the songs will be way easier to link to real life instead of the lore counterpart.)
It's split into three parts, let me know what you think!