Titus Drautos, as both the commander of the Kingsglaive and General Glauca of the Niflheim Empire, shows starkly different personalities but there are two things that he openly shows in both persona: His strictness and preference to fight on the battlefield alongside his troops as well as his lingering in the past over the loss of his home.
As the leader of the Kingsglaive, Drautos holds his subordinates to an extremely high standard and apparent from having been in battle for so long and likely lost his share of comrades before joining Niflheim, has become an emotionally cold person in the field of battle, as shown by how he admonishes Nyx for disobeying his order despite how Libertus would have died had he not saved him. Though he can show kindness and empathy at times, as shown by how he comforted Libertus over his discomfort of the peace treaty and later personally told him and Nyx of Crowe's death, it is unknown how much of this is really true, though the fact that he offered his Glaives to join Niflheim indicates he saw them as kindred spirits and sympathized with them as Regis had offered up their homes in exchange for Insomnia being untouched.
As Glauca he is callous and murderous and has no qualms killing his fellow Lucians. Glauca seems to have no major distinction between friend or foe, as he is willing to kill Deputy High Commander Ravus Nox Fleuret when he tries to wield the Ring of the Lucii. He only works with the empire as it has promised him the liberation of his homeland and states only the honor of the homelands should matter for the Glaives. Although he once served Regis for the honor of his home, Glauca came to resent him for merely remaining in Insomnia, deeming him a traitor and ruthlessly killing him, making a point to show how much he resented Regis, though Drautos may have not completely lost his respect for the king, as he bows down to him.
Although no less harsh on Nyx despite having personally trained him, it is known that Nyx was the closest to Drautos out of the Glaives, having looked up to him. As Glauca, Drautos shows mercy towards Nyx, only defending himself from Nyx's assault, and despite being enemies, when Nyx was not aware of his true nature, Drautos appears to be concerned for his protégé, checking his wounds, and offers him a chance to surrender when his cover was blown. As they fight, Drautos persistently tries to convince Nyx to join him and when Nyx seems to have reached his limit, he leaves him alive. As Drautos is defeated, he accepts Nyx's proclamation that their homes have a hope due to Regis and dies with a smile.
Drautos is an extremely skilled and powerful combatant, who as the leader of the Kingsglaive was considered to be second only to Cor in terms of skill while as General Glauca, he is considered Niflheim's strongest warrior. He is an accomplished instructor in the arts of combat as well, having trained the Glaives himself, his protégé Nyx Ulric in particular being the second strongest of the Kingsglaive just under Drautos. Having amazing skills with a sword, while adorning the armor of Glauca, Drautos's physical capabilities are tremendously enhanced. Despite it's heavy looks, he can move at astonishing speed. His skills and power are best shown by how he was able to slaughter the entire council, even besting Clarus Amiticia, though he had more difficulty with him, and fight the Ring of the Lucii empowered Nyx equally.
Drautos is an extremely competent leader, being entrusted with leading the Kingsglaive and the forces of Niflheim, and was deceptive enough to conceal his true allegiance.
Titus lost his hometown at some point, he began working for the empire as General Glauca, and under this pseudonym became the high commander of the imperial army. When Niflheim attacked Tenebrae in an attempt to kill King Regis and his young son, Prince Noctis, Glauca murdered Queen Sylva. Regis and Noctis escaped, but Tenebrae was annexed to the empire and its prince and princess fell into imperial custody.
After the Kingsglaive returns to the Crown City of Insomnia, King Regis deliberates over whether to accept Niflheim's peace treaty. Regis wants to keep his son safe, and decides to send him away from the city before the signing ceremonies. As depicted in Final Fantasy XV Prologue Parting Ways, Ignis Scientia drives Noctis to meet the king the day before his departure in the Audi R8 Star of Lucis; they use Noctis's car because Captain Drautos wants to use it to ferry guests to the treaty-signing ceremony later.
Now working as Glauca, Titus orders him to go to Section D of the city. This turns out to be a trap, and through Libertus's intervention, it is revealed Drautos is Imperial General Glauca. He battles Nyx who gained the power to command the statues of the Old Wall from the Ring of the Lucii. Libertus flees Insomnia with Lunafreya and the ring. Glauca is severely wounded when Nyx stabs him in the chest with his kukris.
When Noctis arrives in the ruins of Insomnia ten years later, he recovers Nyx's weapons from a powerful daemon. Whether this is what became of Drautos is unknown, but the last time Nyx had his kukris was when he plunged them into Glauca.