|Box Animal||Heavy Rain Elephant|
|Manga Debut||Chapter 221|
|Anime Debut||Episode 137|
Olgert is Rasiel's butler and Belphegor's previous butler. However, he states that he chooses to stay by the side of the true king, who he believes is Rasiel. He wears a black butler's outfit and is bald. He appears to have four symmetrical scars on his face.
Olgert appears during the Varia's Invasion of the Millefiore's branch in Italy. After Bel and Flan split off from the group to scour the area, he and Rasiel confront them. The fight was cut short as Rasiel, having believed that he had killed Bel and Flan with his Storm Bats, led Olgert to the castle that was taken by the Varia. Olgert fought Xanxus in defense of Rasiel, but Olgert, along with his Heavy Rain Elephants and Rain Pelican, was petrified by Xanxus' Box Weapon and his "statue" destroyed.
- Heavy Rain Elephant - Olgert's Rain-attribute Box Weapon. It was stated as a common Box Weapon among Millefiore subordinates, easily controlled and reproduced, with enough power itself to level an entire castle.
- Rain Pelican - Olgert's Rain-attribute Box Weapon. It is able to clad itself in Rain Flames to form a shield.
|Leaders||Byakuran • Yuni|
|Six Funeral Wreaths:||Ghost • Kikyo • Bluebell • Zakuro • Torikabuto • Daisy|
|Fake Funeral Wreaths:||Shoichi Irie • Gamma • Genkishi • Glo Xinia • Rasiel|
|Subordinates:||Baishana • Iris Hepburn • Olgert • Ginger Bread • Spanner • Nigella Beabankul • Dendro Chilum • Tazaru • Nosaru • Leonardo Lippi|
|Weapons:||Rings • Box Weapons • Dying Will Flames • Battery Boxes|
|Specials:||Illusions • Dying Will Flame Boots • Boxes of Carnage|