The bad news was that the two guards beyond the blast door controlling the sentry guns could already interfere in the battle from where they were. So he had to eliminate his current enemies quickly or things would become very difficult if they gang up on him with the guns.
Unlike the sentry guns in the human farm. These ones were fewer in number and also not manned by a system. The sentry guns couldn't automatically shoot at intruders since the establishment was supposed to accept unknown people.
Besides, his current identity was that of a guard, so even if they were manned by an automated system, they wouldn't be able to harm him. Unfortunately, they were being controlled by humans. Those humans heard the explosion and have begun to turn the sentry guns to the center of the explosion.
Black Mantis had also heard the explosion. He began to panic immediately. He stood up and began pacing about.