The next Avatar is an earthbender, and sadly the most common name I've seen for this one is Terra.
Seriously? Its an Avatar, not a Pokemon gym leader.
Because gym leader names are almost always puns that go with the gym type ok
I like the name Riley for a girl because it sounds tomboy-ish, For a guy... Patrick (generic guy-name that I like) or... I dunno.
Yes Western names, because I'm not so familiar with Eastern ones 8|