Brachion consists of a core connected to a set of arms, also called "grapplers". The core will release toxins into the links between it and the grapplers; if the toxins reach the arms, it will cause vital damage and all excised grapplers will regenerate. Segments of the arm can be pinched to deter the progression of the toxin to the skin. After each grappler is removed, the arms will retract, forcing Brachion to regenerate, and putting a considerable deal of strain on the core.
When the toxin reaches a pinched segment of the arm, the pinched segment will expand to normal and the toxin will return to the start of the arm. Use this to your advantage, and plan out the pinching so it gives you the most time spent not worrying about the toxin.
Most players opt to pinch segments of each arm where the toxin is currently located. This forces the toxin all the way back to the core while keeping the arm pinched. It takes a while before the toxin begins moving again, buying extra time to extract the grapplers.