The final bosses of Malum District, the Black Rabbit Brotherhood, are a notorious group of killers that reign over the area, using their strength to force the residents to pay Ergo for "protection". As a group of four siblings, this boss has you fighting against not one but four different foes that you'll have to take down — though fret not, as it's not all simultaneously.
Considering the different builds that are available for Lies Of P, I will keep mine out of the guide — it makes the most sense to explain how to defeat the boss rather than what build to use. But, for those curious, I took my Wintry Rapier with its original blade and handle at +5, and Pinocchio was level 56 with 23 Vitality, 19 Vigor, and 34 Technique; everything else was at its default.
Malum District being one of the later areas in the game early game, the Black Rabbit Brotherhood snags the title for one of the most challenging bosses that you'll be facing, though a lot of what makes them terrifying is just how frightening it can seem to fight four enemies at a time. Take a breath and calm down, as the jitters will only serve against you, and adrenaline will only make you miss the ever-crucial Perfect Blocks that you'll need to get through this.
Before you start off the fight, it's worth noting that if you've been saving your Star Fragments, now is the time to take advantage of them. That said, however, refrain from using this until you feel confident enough that you won't spend too many of them — you don't want to be out by the time you reach the final boss. Accept that no matter how you spin it, the Black Rabbit Brotherhood will likely take a few dozen tries before you can feasibly try to beat them, as you'll have four kits of abilities to learn and a lot of nerves to conquer.
You'll start first with the Eldest Brother, the one that is considered the actual boss of the bunch — while it's still terrifying to have two enemies on the battlefield, the other three siblings are actually not much stronger than the hard special foes scattered across the overworld. In fact, once you nail a trick down, they can be stupidly easy to beat, but more on that later.
The Eldest Brother has a few tricks up his sleeve and has one of the most expansive kits of attacks from bosses, which makes him seem far more daunting than he is. With Lies of P, as you might know from my tips & tricks, your best bet is always to block earlier rather than later. Guard Regain is a crucial tool for sustainability, and considering you'll be fighting various enemies and the fight can run long depending on your build, you'll want to avoid as much direct damage as possible.
The main boss of this entire fight isn't nearly as hard-hitting as his burly body might make him seem. Though he will down you with just a few hits if you aren't careful: his quick fighting style, despite the broadsword he uses, is actually relatively soft-hitting, especially through your guard. Use this to your advantage to learn when to Perfect Guard or use any openings after his main combos to replenish part of your Guard Regain.
For his attacks specifically, his combos tend to run a little bit on the long side, as most of his attacks will be chained up to four times, though it's worth noting that this is often the exact same attack, just a little bit quicker. This means that once you learn the tells, you can start Perfect Guarding through his combos to eventually Stagger him and deal a Fatal Attack (a misleading name considering it'll practically tickle him, but that's beside the point). Consistently timing his abilities well will make staggering him easy, and once you've started using your Star Fragments and have a Specter at your side, it'll be quite easy to get him past his first phase and into his second one.
At about 75% of his health, his siblings will start coming to join the fight. It'll start with the girl (Youngest of the Black Rabbit Brotherhood), move on to the spear wielder (Battle Maniac of the Black Rabbit Brotherhood), and finally, the one with a rapier (Eccentric of the Black Rabbit Brotherhood). While their combos differ a lot from each other, you don't actually need to learn any of their attacks because I'd mostly recommend Guarding through all of them. While this will chip away at your life a bit, their damage is negligible, and by the time you reach the second phase, your Spectre should still be active.
Instead, whether you're solo or fighting with a Spectre, your primary purpose should be to try to use their longer combos to get behind them and do a Fatal Attack, which, in this case, is slightly more accurate. After several of these, the siblings will leave the battlefield and never return. Your main focus when fighting them should always be to try to get behind them, as regular attacks will only slowly chip at their HP, making the fight drag on for far longer than you'll want it.
While the siblings are around, it's worth noting that the Eldest Brother will not usually attack you so long as you keep your distance. If you keep in mind where he is at all times, you can comfortably give him your back because the only attack he'll consistently do is a charge, which he grunts before he does. Once you hear the grunt, dodge roll out of the way, and you should be able to avoid his attack (and likely the sibling's, too). This is especially true because even if you perfectly guard either of the two attacks coming your way, you'll still be susceptible to another one, as Lies of P doesn't give you a moment of invulnerability after one of these.
The toughest of the siblings is definitely Eccentric of the Black Rabbit Brotherhood (the last one), as hitting him with a Fatal Attack is the hardest of the bunch, but his attacks are negligible in damage, and if you happen to have your Spectre by this point (depending entirely on each individual fight, as it was pretty inconsistent how often my Spectre survived), focusing him down should be easy. In fact, every time a new sibling comes around, your main goal should be to remove them from the fight as quickly as possible, as although that will unlock the Eldest Brother's abilities once again, having them out of the way can give you the one-on-one combat necessary to defeat them.
The most important thing when fighting the Black Rabbit Brotherhood is to exercise persistence and patience. Despite how frustrating and infuriating they might be, they are definitely a group of foes you can defeat, and they do not make up for quality with quantity. Whether it's using your Spectre to even the playing field or fighting them one-on-one, you can defeat them with persistence and using each new death to learn the combos. And if you need to, take a break — they will be there waiting for you once you're ready to fight them again.