Big SISTER 1/3

Weakness None
Boss Third

Big SISTER 1/3 is a Boss in The Surge. Big SISTER 1/3 is an extremely difficult boss fight, against a large force of robotics being controled by a "brain".


Big SISTER 1/3 Location



Big SISTER 1/3 Drop



Big SISTER 1/3 Strategy

The strategy here is the arms will alternate attacking one of 3 attacks, a lunge, a smash attack and a swipe attack. You'll have to learn to recognize which is which. Every second arm attack a laser will try to hit where your standing from the front and then a second or so later again where your standing from the back, so be sure to avoid that and don't attack unless you're sure you won't get hit. That's it for phase 1.

In phase 2 you will need to defeat the arms and the "head". The camera angle can be tricky here, but the best idea is to stay in one of the closest corners because only 2 arms can hit you there. Take one arm down and then another and then move to the other side and repeat. The laser will keep attacking you, so besure to dodge it and after a little while the floor will turn electric damaging you, so don't take too long. Make sure you have lots of heals and play aggressively, but only in these corners.

Finally in the last phase you will need to get close to the head, dodging it as you approach since it likes to lunge and you'll have to fight it in a zoomed out sort of setting. It's a bit weird, and it will take you a bit to get used to it, but you cannot move backwards or the camera will zoom in and if you do this a lot you will get killed by the camera angle, so learn to force yourself to stay close to the boss. Running attacks don't seem to work here, at least not the way they do normally, so slow swinging weapons that use these attacks are at a serious disadvantage. I suggest switching to something that has a faster attack speed for this part, or for the fight entirely. Really in this phase you want to play aggressively, you just don't want to get grabbed when he goes up off screen and comes down, so if you see him go up off screen dodge back and wait.

Big SISTER 1/3 Hardcore Strategy

To get hardcore kill, you must not kill any arms in phrase 2 and go for the head immediately.

Big SISTER 1/3 Tips/Notes

  • If you are using a heavy weapon or Single-Rigged you may want to switch to something faster for this fight.
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    • Anonymous

      14 Mar 2020 16:36  

      When I get too close to the bosses corners my camera spins to look at the arm across from me and then I die. I don't know if it's an attack that just one shots cause I cant see at all neither myself or the boss

      • Anonymous

        25 May 2019 19:09  

        I didnt know i was supposed to lock on to the head during phrase 2/3.........cuz i was playing in dark souls.........

        • Anonymous

          27 Apr 2019 15:35  

          So, I found a bug that respawns the boss. I haven’t fought it again to see if doing so is game-breaking, though, so fair warning. So, I had the security armor and rig and was going back through the game opening security doors. I looked up the location of the doors and the one in R&D said something like, “as soon as you enter this area from the Big SISTR 1/3 fight, it should be right there.” So, I crossed the corpse of the Big SISTR, over to where you go after the fight. I followed the path, and, when I got to the drop down into R&D, I jumped in. Then, my game crashed. When I started it back up again, I found that the corpse path was no longer there, because Big SISTR respawned and was just there as if I didn’t already destroy her. Once again, I haven’t fought her again, so, I don’t know if doing so breaks the game. It’s just a weird bug I found.

          • 14 Jan 2019 04:56  

            I'm late for the party, but I didn't even bother with arms in 2nd stage. Just get to the corner behind the head and they will disengage as they'll be out of range. The head itself is easy once you lock on it and get use to that far camera (use manual targeting). Swipe attacks won't reach you and when it's getting ready for that top-down hit just move to the opposite corner. Don't get pushed to the center and you'll be fine. The biggest problem is locking. It's dumb, that during first stage arms are switchable same way parts of the body are, but during the second stage arms and head are being treated as separate enemies (LB/L1 + left stick click on a gamepad). Hope it's useful to anyone.

            • Anonymous

              29 Dec 2018 01:34  

              Honest this boss is too easy compared to every other boss, use single rigged and use your slide attacks, easy win even a caveman could do it, I did it first try on my first run and on NG+, hardcore kill is easy, ripping off its arms is honestly wasted time with just how quick she goes down, so yeah, as the saying goes, Git Gud, but you don’t need to be good when single rigs exist.

              • Anonymous

                16 Sep 2018 11:10  

                Liquidator full set will weaken the energy attacks, phase one, move far back, you can see better and the sweeping blows won't get you. You can just rush to the head in phase three, its grapple isn't that powerful and liquidator can handle the element dmg.

                • Anonymous

                  25 May 2018 13:02  

                  Rolling under `the brain` in 2nd phase & attacking from behind (standing near its body basement) makes you invincible against grab attack. Still need to watch out for hands on sides though (if you did not eliminate them). Makes an easy fight.

                  • Anonymous

                    24 May 2017 11:57  

                    I went in completely clueless and ignorant and beat her on the second try, including the 2.0 weapon. Easiest boss in the game, I'd say. In the first phase the arms can't touch you if you stand in the corner diagonally apart from the respective arm. After that run to the head and beat her up. Best places to stand when not attacking are to the extreme left and right, as far to the background of the level as possible. Dodge like a maniac and attack her whenever she's not traying to grab you. I lost my lock mid-fight - might actually be easier than to deal with the horrible camera.

                    • Anonymous

                      22 May 2017 20:26  

                      For the hardcore kill :
                      Maybe the assumption that you must not kill ANY arm in phase 2 is wrong : I just watch this video ( He gets the v2 and kills 2 arms during phase 2. I read someone who didn't get it after killing 4+ arms. So maybe 2 or 3 arms is the max you can kill to get the v2. If so, kill the arms the nearest of the core, it makes the fight a LOT easier.

                      I will try it and update when done.

                      • Anonymous

                        17 May 2017 20:45  

                        Was able to defeat her in Hardmode...took me a couple of tries...the camera literally killed me several times...

                        Hardmode means ignoring Phase 2. Fighting the Head without killing the welding arms.
                        Its Hardmode because 2 welding arms are attacking you from behind.

                        With the right Strategy it was easy, since i still had the better 50% of my Potions.
                        I used the Firedevil V2 (from second boss)
                        Phase 1:
                        Stay at the back, touch the Fence. Thats when the Arms do their Lunge attack in the most time.
                        Dodge when they lunge and attack them with R1,R1,R2.
                        Phase 2:
                        Phase 3:
                        At the first the Boss MAY kick you back once, but you CAN dodge that and he may miss you if you stick to the outer edge of either side.
                        Attack the Pole in the Back, where the Boss is mounted for about 200 dmg, you'll see a spark.
                        Then attack the Boss itself, Camera WILL lock on the Boss itself when you hit him once. Otherwise you might die of broken Camera >_>.
                        Dodge all attacks and try to say to the outer front (from your perspective) of either side, some attacks and the welding arms can't hit you there.
                        I just attacked the boss with my Firedevil R1,R1,R2 combo (Ring of Fire) and dodged...TRY not to hit the welding arms.

                        It is possible to used the PAX Imperator, but the Weapon is too slow for the Boss, making it much harder.

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