Bloody Gate is a gunwall acting as mini-boss in the Final Fortress. He is fought halfway through the stage, and has not appeared since then.
Bloody Gate has a relatively simple attack pattern. The walls move up and down sporadically, all the while Bloody Gate's four laser cannons are targeting you. These cannons can be destroyed easily, but they regenerate a few moments later. In addition to all this, he has two hatches which are constantly generating Duckers. These hatches can't be destroyed. Bloody Gate has two cores, each core has 5 barriers.