Befitting his oldness, August's demeanor is among the more cool and stern of Zeref's Shields, rarely expressing strong emotions; he quickly settled down after seeing God Serena being slain up close. Wise and often speaking cryptic, Brandish μ, herself a Shield, also labeled him the wisest of Zeref's Shields. Additionally, despite his status as one of the world's strongest, he's also aware of and accepts his limits, saying to another Shield that they, together, still had no chance of defeating Acnologia himself (whereas the strongest female of the Spriggan 12, Irene Belserion, sanguinely dared confronting the Dragon King all by her lonesome).
Whereas, according to Jacob Lessio, August is truly "bad news", lacking the barest sense of humor; he's very gentle by word of Brandish, reportedly the easiest one to talk things out with among the Spriggan 12, a statement later proven well-founded. In fact, August's mellow bearing is such that, regarding enemies, he told God Serena to desist from killing, of all people, the helpless four then-strongest of Ishgar's Wizard Saints, and wanted to grant Mirajane Strauss a quick demise by shooting through her heart; regarding comrades, he cares much for and is protective at least of fellow Shields, saying that it's a terrible thing to lose a comrade after having saved Ajeel Ramal (possibly his life) from Laxus Dreyar, asking if Jacob is still alive after the latter had gone on ahead to fight Fairy Tail, and saying that the dead God Serena remains inside his heart. He also rightfully deduced that Brandish stabbing him wasn't voluntary, consequently putting her asleep rather than hurting her in return. August has even shown his distaste for barbaric cruelty set upon enemies, as he was disgusted witnessing Irene torture Mirajane. Even after defeating Crime Sorcière, rather than killing them, he chose to let them live.
Besides, the elder's loyalty to Zeref (whom he reverently addresses as "Your Majesty", unlike Ajeel's informal behavior, but more casual than Invel's interaction with Zeref) is proven to be near inflexible, considering himself and his colleagues Zeref's pawns only, and likewise reminding Brandish of their dedication of their minds, bodies, and very souls to their emperor, while at first brushing aside Brandish's inability to find meaning in Alvarez's war against Ishgar as her betrayal as an enemy whom he ought to eliminate (in spite of knowing Brandish from her childhood days). And yet, he acknowledges the need for even Zeref to have the infinite Magic Power of Fairy Heart in order to kill Acnologia.
Additionally, Brandish managed to initially convince him into first listening to what Fairy Tail had to say to him rather than immediately proceeding with the plan of obtaining Fairy Heart, by imploring him to understand the senselessness and malevolence of the bloodshed that was their war with Ishgar, and that Fairy Tail wasn't evil (although the fact that seeing Natsu Dragneel seemingly reminded him of something might have also played into that). Then, though, when Mest Gryder used Brandish to attempt to kill him, he instantly decided on utterly annihilating the Fairy Tail members confronting him. As the general of the Spriggan 12, August takes his position seriously, as he reprimanded Irene for ignoring their orders to meet up with their emperor, and gave an intense glare at Larcade Dragneel, for always skipping meetings. August believes that light and darkness do not defy the concept of good and evil, and he believes that true justice in the world lies between love.
Magical Intuition: Lauded as the supreme "Magic King" both past and present, August is rumored to have effortless control over every single element of Magic there is, even possessing more types of Magic than Zeref himself.