Is DJ Sona actually...?
Listen to Sona's voice clips all throughout her Pentakill song, "The Hex Core." She's irrefutably* screaming* for help. I'm not sure what the second part of her loop is, but it sounds like she's pleading against something, like "I a- [static]" or "I can't," but I'm really leaning toward the first one. It sounds like she's started to say something, but it's cut off with a scream or her voice was distorted with feedback. It's worth noting that Sona is mute but not deaf, which implies her vocal cords probably don't work. She can scream like she does in others songs, but probably not speak as clearly as she does here without something to improve her speech. Maybe an... augmentation..?
At 4:14, you can hear laughter after her screams have died down, as opposed to have just stopped looping.
Is DJ Sona just the augmented form of Sona, after Viktor thought he could improve her role in Pentakill? After all, wouldn't it be great to play with a set designed to work with your very consciousness, and potentially be able to vocalize? Having "DJ"-esque modifications gives Pentakill a whole slew of new possibilities, so perhaps it really IS an improvement...
Before you say that DJ Sona looks too different from a Battlecast to be Augmented, take a look at Augmented Singed vs DJ Sona. All of DJ Sona's forms: http://i.imgur.com/h5SQx4o.jpg
Augmented Singed:
http://img2.leaguecraft.com/lol-splash-art/asset/wallpaper_760px_3642.jpg
I don't know about you, but they don't seem too different to me; just different functions. Look at the stylizing and the materials used...
If it turns out that Viktor actually did do this to Sona, that would really shock me. She was screaming for help - for him to stop - and yet here we are with DJ Sona... But on the other hand, she doesn't seem at all unhappy with her new improvements, does she? Perhaps, it was just the augmentation part that was difficult, but afterwards she's made peace and enjoys it? Perhaps, it was just er- a hard pill to swallow?