Despite not being part of my plans, I decided to take Yamato Perpetual Reactor [Shin Megami Tensei IV], Scare Shadow [Saya no Uta] and Skin Thieves [Jimmy and the Pulsating Mass] and sample pieces of each one to create Mechanto Brain's encounter theme. I think it does a good job of clueing the player in that Mechanto Brain isn't like the others. (It also plays when Mechanto Brain tries to convince you not to fight Omega).