Abysmal Knight (anime)

Abysmal Knight was the most powerful Demi-Human monster who happened to be inhabiting in Glastheim, serving Dark Lord. He was also powerful as he said to have taken down numerous adventurers in the past. He was once responsible for "killing" Keough when he, Iruga, Roan and Yufa were investigating Glastheim in the past.

Story
The Abysmal Knight was a fearsome monster as he was said to be roaming around Glastheim, taking down on those who dared to venture into this place. In addition, the blade of his sword which was called "Blade Lost in Darkness" can caused even the purest person to turned evil when he or she was stabbed, just of what it did to Keough.

He once appeared in several flashbacks where he first appeared. When Roan, Yufa, Keough and Iruga were investigating Glastheim, he immediately attacked them. Just when he was about to strike both Roan and Yufa, both Keough and Iruga intervened in time and attacked him. However, he eventually slew Keough as Yufa watched in horror, thus traumatising her due to the incident. However, he was later responsible of turning Keough into evil thanks to his sword.

He later appeared in the final battle in Glastheim. In order to avenge his friend, Iruga engaged him in a fight. Eventually, the Abysmal Knight was destroyed when Iruga, Maya and Judia weakened him with all their powers before he met his demise as he was destroyed by Roan's Holy Cross.