“Wait! This isn’t where you belong, but… your home is sure to be out there, somewhere!“
[His friends warns him about Genesect pointing its weapon at him, Mewtwo demands that he step aside.]
"I’m not moving! I… I promised that one to take it home… Mewtwo! There can’t be any Pokemon… that shouldn’t exist!”
Given that Mewtwo described the Genesect as being creatures that shouldn’t exist in this world– exactly like herself– on more than one occasion… Satoshi’s speech here is meant as much as a case for the Genesect’s existence and ability to change, as well as correcting her own misconception about herself.
Long story short, @rohanite, I’ve found myself thinking Satoshi is one of my favourite characters a little while back, without realizing when that became true, but. I take back what I said, he’s definitely one of my favourites now.