Ho tan : Sifu Toph can you tell me why you invented metal bending?
Toph : Yeah it's not big beal. I invent because I got kidnapping in Ba sing se by two earthbender
The Dark one : You WHAT!
Toph : Well apparently they were hired by my father because he think The Avatar kidnapping me first.
Penga : Who kidnap who? I'm confused
Toph : Anyway when I got kidnap in metal box and I really don't like to be in that shit. So I invent metal bending to escape frome that box. That all!!
Ho tan/The Dark one/Penga: ...
Note : just something on my mind when I know that all of bending learn from nature and animal. And metal bending was invented because Toph don't want to be in metal box Lol
Ps. Pardon for my poor choice of word and grammar.