I think by current rules, Nero would flat out kill banding chains instantly, as making them 0/0 would be akin to decrease and Null, as worded, doesn't protect from discard. I like the magicians, though. While I'm not a fan of mill cards at all, I can see this being useful without being too powerful.
I possibly feel like having Null apply to enhancements alone could be better. It certainly buffs FBTN, but I don't think being able to null characters, unless the mechanic states that it can't discard them, is balanced. Plus, it kinda feels like an infinite decrease at that point, which is kinda odd.
On a side note, I think Emperors have a number convention of 10/# of years they reigned (up to 12). So theoretically, Nero should probably still be a 10/7.
