Be it GM Fiat or not I had not originally intended for there to be three gunsmen however enemy berserk's master is in a position where he is more like a church version of Kiritsugu minus his special gun and bounded field in place of high tier sacramental magics. As a magus hunter he probably has a few friends who'd help him in this war (Edit) Given the situation and Albert's stubborn nature I had to do something for enemy Berserker's situation. Originally he was supposed to be the one holding the gun to Albert's head in this scenario.
The bombs were planted before the group got there and the reason he took his time to show up was because he evacuated the remaining employees to the best of his ability. If I had just him likely Albert, or more likely Lancelot would've done him in. Had to stack the deck hard. Keep in mind this WILL cause a party wipe if you throw the wrench into the engine. Leon may survive due to his water shield ability (Water pipes in the building depends on if Leon can even manage it in time) if just very very barely. Lancelot will die, berserkers will die, Albert will die. Best way out of this is to take the big guy's advice.