thank you!!
[Percy takes hold of the open opportunity while the dragon is busy going after Nico.
He moves as quickly as he can (which isn't very quick seeing as how exhausted he is) out of the dragon's field of vision, assessing the enemy with a keen eye as he does so. The vulnerable parts are taken into account as Percy moves in for a strike, slashing Riptide at the dragon's underside before jumping back in one fluid motion.
He definitely didn't have the energy for this, but that's never stopped him.]