A lowly adventurer getting by on the occasional pickpocket, Klaus's talents were discovered by the entrepreneur Lumier Paris who had him placed among the Solaran Guard in a special division unique to himself. In lay terms, he was a spy. Immediately following the Eighty-Minute War, Klaus stole a set of Lunarian armor and infiltrated Castle Lunaria.
He then ingratiated himself to young Prince Dalyn by helping him remove his brother Diphas from power and "disappearing" him. As Captain Niko, he went on to serve Dalyn for the next several years. During this time, he also met and befriended Daniel Grimoire. When he contracted the Soul Corruption, he forged an alliance with Jeriko and the Shroud before placing himself among the new Knights created by the visionary Amistha under the assumed identity of Nikolai Omega. His forgiving nature soon garnered him the moniker "Saint Nicholas".
Eventually, two of Amistha's Knights abandoned the ranks shortly after having lain siege to the town of Dienara; Gaius and Primus, or as they would come to be known, Usagi and Cardinal, would go on to become ready allies. However, Usagi had become "corrupted" and had no place to go to. Feeling sympathetic, Klaus abandoned his latest post and escorted Usagi to Lunaria, where he was sure he would be accepted by Jeriko's growing brotherhood.