After you reach the mid-stage of Pangzhen in Phantom Blade Zero, you'll be forced to make a decision about exploring for the first time. Up until this point, you'll have enjoyed a very linear progression, but you'll eventually be faced with a choice of whether to explore Lake Miegu or the Mandate Encampment.
If you choose the latter, you'll work your way towards a boss fight with the Chief Disciple of the Seven Stars Formation. But along the way, you'll also have the option to complete a side quest where you can collect six Memory Flowers tied to this group.
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All Seven-Stars Formation Memory Flower Locations
If you're struggling to find these flowers, we have you covered. First of all, we have a complete map showing all the Memory Flowers right here.

But if you need a visual representation of where to find them, here are the locations of each one:
Memory Flower #1

When you reach the Cliffside Walkway Entrance Bell, instead of entering the cave inside the cliff, head up the ladder. Defeat the enemies above, and then you can collect the first Seven-Stars Formation Memory Flower.
Memory Flower #2

After you cross the cliffside wooden platforms and take care of the archers, you'll find the Mandate Valley Gate Key. After collecting this, cut the nearby chain and swing over to the other side, where you'll find the second Memory Flower.
Memory Flower #3

Just as you reach the Beneath the Watchtower Bell, before you use your Dread Axe to break down the barricade and take on the boss waiting on the other side, head left of the bell and up onto the raised wooden platforms, where you'll find another Memory Flower in this collection.
Memory Flower #4

Also starting from the Beneath the Watchtower Bell, head through the battlefield stacked with dead bodies behind you, and down into the valley through the cliffs you just came through. You'll come to the barricade where you met a friendly NPC on the other side near the Cliffside Walkway Entrance Bell. On this side of the barricade is another Memory Flower.
Memory Flower #5

When you reach the Dovecote Bell, you'll want to head all the way around the Dovecote tower and hidden away behind will be your fifth Memory Flower of the Seven-Stars Formation.
Memory Flower #6

After you choose whether to fight or spare Red when you reach the Dovecote Bell and climb the tower. You can swing on a chain at the top of the tower and then use your newly acquired Bashpole to enter a cave inside a nearby cliff. Use the wooden panels to jump and reach the flower.
As far as we can tell, aside from the 10% buff to your overall HP added for collecting this set, there is no other reward or consequence for collecting all of these Memory Flowers. However, for the 10% buff alone, we suggest you pick these up as you go.