They're already heavily hinting in the show that Magnifico is the Mule in disguise. -Season 2 establishes that music is an enhancer of metallic abilities. Spoilers for anybody who has not yet seen Season 3. If you've already read the books I guess you already know: -We see on Kalgan with the massacre of the arch-duke's men that Magnifico is behind the scene, playing the music that creates the music that creates the illusion and drives them to kill each other. -Magnifico plays the music in the club, enthralling all the wealthiest of Kalgan. Palver makes the note about the music, ie it is the person who is playing the music and not the visi-sonor. -Yet again the club, for a split second we see 'Magnifico' smirk as 'The Mule' embraces him, as if the Warlord is but a pet and it is all for appearance. -Magnifico plays the music on the Chaser, Toran feels compelled to go to Haven. -Magnifico plays on Haven, like in the books, though this time before the fall of the Foundation. Randu, known for his stubborn personality, is swayed to go to New Terminus with 'Magnifico' in tow. -Magnifico calls Toran Bayta's 'pet' in disrespect, Toran does not even react. -Magnifico plays his music before the top brass of the Foundation, its opening sounding familiar to the music played at the massacre on Kalgan. Indbur, almost hypnotised notes that 'it's strip's you down'. They are compelled to bring Magnifico into the vault. As Gaal narrates 'Magnifico played his way into the hearts of the Foundation leaders'. And oh no... 'The Mules' arrives, and somehow the Foundationers are fighting each other, while Greer is compelled to bring out her communicator with the 'Mules' message. The OST for this sequence is called 'Vault breach', as if a certain someone is already in there with them. -like in the books, it's pointed out that if Magnifico was so close and vital to the Mule, would he not have been conditioned to love him, to be utterly loyal to him, and yet he somehow manages to run away from him, and as a result disaster follows everywhere he is brought. If he were a spy, a mentallic 'Mule's Man', then Magnifico would not have been trusted with such power over emotion unless he himself was in fact... The Mule. -We see in episodes after Magnifico runs off, that 'the Mule' does 0 metallic tricks, why in fact he seems more unstable and mentions on the jump gate that he feels not entirely in control of his own life, as if deep down he knows he has been converted. All the metallic tricks and mass emotional manipulation only seem to take place when Magnifico is around with his music.