The Giant Shigandang is the largest boss in Black Myth Wukong, by a very long way. It's also pretty dang well-hidden, both by the environment and by the prerequisite of collecting some rather well-hidden items across the previous Chapters. The Giant Shigandang only spawns in Chapter 6 if you have collected the four Skandha items from the other Chapters of Black Myth: Wukong. Here's where to get each of them:

Skandha Of Form (Chapter 1): Interact with the head-shaped rock on the river edge in Back Hills.
Skandha Of Feeling (Chapter 2): Defeat Shigandang by collecting all six Buddha's Eyeballs. https://youtu.be/j8ZSjqiMK3I
Skandha Of Thought (Chapter 3): Jump off the cliff beside the "Mindfulness Cliff" Shrine and follow the hidden path to the end.
Skandha Of Choice (Chapter 4): Loot the Buddha head at the end of the river in the Purifying Spring.
If you've collected all of these Skandha items, then once you reach the "Mantis-Catching Swamp" Shrine in Chapter 6, fly up to the clifftop ahead of you, and follow the middle path through the ravine. You'll soon come to a gigantic boss arena, at the centre of which is the Giant Shigandang.

The first thing to do is fly down towards the ground if you're on Somersault Cloud, because it lets out a roar that knocks you off the Cloud, and if you're up high, the fall could be fatal.

Now then, onto the fight itself. The Giant Shigandang is another boss that can't be fought conventionally - it's just too big. Instead, hang around on the very edge of its arm range, and jump over its shockwave attacks. Wait for a moment where it leaves its arm on the ground for a few seconds, and run towards it. Target the blue crystals on its arms with your largest and most powerful attacks; each time you break a crystal, it deals enormous damage. Rinse and repeat this process, and the Giant Shigandang will fall very quickly.

Once you defeat the Giant Shigandang, climb up its arm to trigger a cutscene, during which you obtain the fifth and final Skandha item: the Skandha Of Consciousness. Take all five Skandhas to Xu Dog at Zodiac Village, and he'll give you a special Celestial Pill which increases all your attributes at once. Pretty neat.

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