So gruzers always spawn in the pattern in the picture regardless of when/where gruz mom dies and where her corpse is facing. To try to maximize dmg at the beginning, where the positions are consistent, you can stand close to the end of the tail (doesnt matter where the corpse is facing, but it works better if the tail is looking right bc of the gruzzer thats the highest), do two full jump once you see her last shake (3rd) and slash on the second one on the way down. If you stand closer to gruz mom you are risking more getting hit but you have a higher chance of hitting the 5th and 6th gruzzer and the one on top, if you stand further you will get hit less but hiting more gruzzers is more difficult, find the balance you prefer. You should priotirize hiting the 4 on top. Best approach i found is to do these jumps, hit the 4 on top and the 2 next ones if you are lucky/precise with your slash, kill the gruzers that inmediatly go towards you (especially the ones you havent damaged) and then try to finish out the rest, by this point basically every gruzzer should be damaged so you can kill them in one blow. You can also try to slash earlier after the 2 jumps if you are having trouble hiting the one on top right away or with gruzzers on the ceiling having 8 health or to slash a bit later to try to hit 5th and 6th gruzzers more often, again, your preference.
Make sure to react to the third screenshake insteadd of predicting bc you will be too fast if you predict.
Also, keep in mind its still rng and can go very wrong, I got pretty lucky in the video.
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