This scene broke me. Plain and simple. This series had already ripped my heart right out of my chest with Sayaka's story, and then this episode -- and this scene in particular -- came along to feed me the ashes. And I don't even feel shame in admitting it.
"Hey... I've got an idea... How about we both become Witches? Then we can tear up this rotten world together...until there's no more evil, no more sadness, until there's nothing left... We'll break, and smash, and pound it into dust... What if we did that... Wouldn't that be great...?"