Natsu, Still not done, He feels incredibly tired but fights against it, adrenaline still pumping through him, He feels a source of fire..A heart of fire inside the Titan..He needs it, Natsu lets out a loud "RAAAAAAAAAAAAAGGGGGGHHHHHHHHH!" Before sprinting toward the Titan while it's preoccupied, he begins slamming his fists into the metal robotics chest, and screaming "Fire Dragon Iron Fist!" as his hands slam into fire, somehow, instead of his Magical Energy going down..It is raising..Adrenaline is giving him the boost, He begins channeling all his power to his punches, making sure that he is denting through, so he can finally break through the metal to retrieve the heart of fire.