Not a Hero's Mutated Lucas fight is the final part of the DLC, with more contamination problems to deal with as you tackle a huge powerful boss.
If you need a guide to other areas, our Resident Evil 7 Not a Hero walkthrough can help.
Want more help? Our Resident Evil 7 walkthrough provides step-by-step instructions on how to survive the main story, as well as finding the Shotgun, Grenade Launcher and the game's many Lockpicks and Treasure Photos. Meanwhile, our Antique Coins locations, Mr Everywhere statue locations and File locations lists will help you find every available collectible on Normal and Easy difficulties.
Mutated Lucas boss fight
Once you have completed both the Shield Machine encounter and explored the Research Facility, you'll finally come face-to-face with Lucas. Well, a Mutated version of him.
Once you're in the boss room that follows the safe room, grab what ammo lying around while Lucas talks until the boss fight triggers.
This boss basically has you shoot the glowing red spots on Lucas as he stalks you in this room. At all times, keep a healthy distance; use the middle console as a divider between you at Lucas, and when he comes round the corner, take a few shots, wait until he follows and continue round.
He has a multiple swing attack which can cause you some bother, so you want to spot it early and avoid it.
There is various ammo lying around, but even if you are low on the more powerful types, then standard handgun rounds will damage Lucas. With enough damage to his head, he will expose his chest, which you can continue to shoot further.
Eventually, he will mutate once more and the room will fill with spores. Your oxygen will run down, and so you need to replenish them regularly using the tanks on the far wall (they glow green through the spore haze). They will alternate from one to the other, and though they will replenish your oxygen instantly, don't leave it until the last minute to do so.
We'd recommend waiting for Lucas to be on the far other side of the room, or standing still with his chest exposed, giving you ample opportunity to run over and get oxygen. We topped up at the 30% mark and it always activated again with enough time, so don't feel you need rush this part of the fight.
It's otherwise the same process as before, shooting the glowing red head or chest. He will guard his chest more - simply wait until he moves his arm away - climb over the central console to chase you faster, and can spit gunk at you from a distance, but again, if you stay far enough away and keep note of where he is coming from, then you should be fine.
If you are caught by any attacks, then as with the oxygen, get as far away as you can before healing and getting back into the fight.
Keep chipping away with whatever rounds you have and replenishing your oxygen, and he'll soon be done for, marking the end of the DLC. Enjoy the ending!
If you want to replay, then a harder difficulty will unlock (which offers an extra Trophy / Achievement) as well as an additional scope for the automatic.