Naofumi has a fairly strong master-pet relationship with the child Gaerion, and a rather professional relationship with the adult one. The adult Gaerion, partially unbeknownst to Naofumi, has been a powerful catalyst in strengthening his Wrath Shield over time. His soul entered the sheild during the fight against hiss own zombified corpse and gave the hero's shield the ability to use the dragon's flames as a counter attack. Naofumi is stunned by the fact that Gaerion is so proud, even when admitting rather shameful things like the fact he's the weakest of his kind or the fact that he's still weaker than Firo. Both Gaerion are willing to listen to Naofumi's orders, and share his hatred for the sword hero, Ren, until they ultimately settle things with him. Gaerion draws strength from Naofumi's Shield of Wrath just as Firo does, but since he's also a source of power for it he shows much more authority over that power. Even before then, being the Shield Hero's dragon has already made the adult Gaerion far more powerful than he was in his own life, to the point where he absolutely dominates Ren, the one who killed him in that life, while the latter is powered up by a Curse Series weapon, and ultimately defeats him. He has agreed to use his power to assist Naofumi if Naofumi brings him the Dragon Emperor's cores, which would make him even stronger and thus even more useful to Naofumi anyway. The Dragon Emperor's memories also become a useful source of information via Gaerion.