Good thing Korra can restore bending (and got hers back fully), otherwise Pretty Boy here would be attending Lost Bending Anonymous:
Tenzin: Alright everybody, we got a new friend named Tahno. He's a former pro-bender, say hi.
Lin, Zolt and Shin: Hi Tahno.
Tahno: Hey everyone-wait, where's Korra?
Jinora: She suffered a complete psychological breakdown yesterday and is currently in the same asylum that Princess Azula of the Fire Nation attended following her defeat at the end of the Hundred Year War. Amon and Tarrlok were miraculously captured a week ago just when the latter was having suicidal thoughts and after Amon somehow debended himself.