A youth of the once-celebrated militaristic Wilhelm family, career military was the natural choice for young Otto- his star was in ascendance, and while he climbed the ranks of the military, it did so as well in the ranks of nobility following his marriage into the influential and prestigious Blakros family of Taldor.
The dreams and aspirations seemed to come into fruitition for the follower of Cayden Cailean, to whom the halfling gave thanks to for his many fortunes. Eventually, he received the command of a garrison near the World Wound of Avistan- mostly due to the machinations of the Blakros family.
The inexperience of command was something that the young noble thought irrelevant- after all, he had been well-educated in the finest of cavalier traditions, and felt competent that under his command, the garrison and it's commander would gain both prestige and fame.
All these delusion came to an end when one cold night Sir Otto was awakened by sounds of screams of the dying- the garrison had come under the attack of demonic forces from the Wound. He hid in terror, the terrors of the night forever imprinted into his memory. By sheer luck, he was overlooked by the invaders, who slaughtered the defenders to the man in diabolical and sadistic fervor, going on for hours. After the last embers of torches and firepits dimmed and went out, the wails of the anguished survivors did as well, snuffed out one by one.
In the aftermath, Sir Otto fled- and after making an account of the horrors he had witnessed, he lost his rank, his command and whatever hopes he had for a bright future. His marriage turned sour and cold, and unable to deal with the recurring nightmares, he took to drinking to still the echoes of the voices of the dying, repeating in his mind.
Therefore, perhaps it was a combination of a drunken stupor, the need to absolve himself of his cowardice and sin in the eyes of his wife and himself, or simply end his torment in death's embrace that got him to sign up with the Pathfinder lodge of Taldor. Or just rake enough coin for his next bar tap, who knows.
Regardless of the cause, the stout young nobleman rides into battle with heavy heart and the stink of booze ever on his breath, embracing either outcome with the same devil may care attitude.