Also known as: ラグナス
Lagunas (ラグナス Ragunasu) is the younger brother of Yuitia (Seihou) and the fifth boss and sixth midboss of Banshiryuu. He refused anyone to enter RedStorm on Mars as Yuitia was fused with a machine in RedStorm, which cause machinery to go on a rampage. He was trying to protect her, aware that Yuitia was the cause of the incident. He was worried that the heroine was going to "get rid of her" instead of leaving her in pain, so he refused anyone to go near her and he'll fight them. He has Yuuta Kirishima working for him.
https://en.touhouwiki.net/wiki/Lagunas