Thread:ADour/@comment-12959254-20140503195635/@comment-4651179-20140503205539

Like I said: Mission Marvel features the Marvel characters as part of the universe of Phineas and Ferb, so basically by creating those characters we would be covering the universe of Phineas and Ferb, and we shouldn't do that.

I've watched the episode, and there's no evidence it's not canon with the rest of the series.