You may not know of the "Vanguard" achievements, but you will definitely know of the accomplishments of "Night Owl".
As the ex Commander of the Sacred Vanguard, he contributed greatly to the Element War, and was the first to disclose the evil doings of the Glacier Corporation.
"Night Owl" was already an excellent soldier since young. Due to his capabilities, he was scouted to join the "Silver Shield" for training, and then assigned to "Glacier" as the youngest ever security leader. Initially, like many others, "Night Owl" believed that the research done by "Glacier" are for the benefits of mankind. However, he accidentally obtained information on the true intentions of "Project Prometheus". Right away, he decided that Glacier had to be stopped. Glacier went all out to try and stop Night Owl but to no avail.
"Project Prometheus" was subsequently revealed to the whole world and Glacier crumbled. Althought Night Owl had helped to divert one of the most dangerous events to mankind, but the likes of Night Blade still continues to create chaos.
In his own words: "We may have won the battle, but we have yet to win the war. We will not rest till the world is finally at peace."