You can tell from Mako’s movements once he got up after the blast that his strength was weakened from being bloodbent for so long. At full strength this blast would have done more than send Amon across the room, and did this while being bloodbent. And then picked up Korra after💪
Michael Dante Dimartino: “Since Mako wasn’t dating anymore, he was burying himself in books and studying. Reading on the airship and stuff. He’a a lot smarter now.”