Ginga Densetsu Weed Orion

Ginga Densetsu Weed Orion summary:

The continuation of the adventures of the Ouu army. The story is centered around Weed's children ? Sirius, Orion, Rigel, and Bellatrix and several other children of Ouu's veterans. New characters have been introduced such as Kurohabaki Masamune, the current main antagonist and leader of the notorious Kurohabaki Clan. Source: Ginga Wiki