After collecting the flower, jump down and climb back up from where we previously went up to kill the archer.
There's a Dust near the shield on the left. Collect it and continue climbing up.
There's another Dust behind the box under the stairs. Collect it and then head up the stairs.
Defeat the enemies above and collect the Dust.
You'll need to perform some maneuvers while sliding down ahead. Halfway through, jump back. If you're not sure how to do it, don't worry—just fall down and collect the Dust in front.
Climb back down from where we just went up. Don't go up the stairs yet; stand to the left of the stairs, where you can see a Memory Flower below (we went up earlier to collect the Dust; otherwise, we could have collected the flower directly from here).
We can jump and use left-click basic attacks to reach this platform and collect the flower.
There's also an item next to the flower.
This flower is Memory Flower #1 of "Huang Xingzi".
