After obtaining the flower, climb up the wall to the left of the save point. Once you reach the top, enter the boss battle against "The Brute and The Saw".
When fighting it, pay close attention to its red-glowing grab attack, which has a wind-up animation. This grab deals massive damage. Its other skills are nothing special.
In its second phase, it deals more damage but becomes more fragile, making it ideal for an all-out assault. The second phase is actually easier since it lacks the grab attack from the first phase.
Defeat it to obtain the weapon "Severed Limb Saw".
