A suspenseful level, though not much is going on, with much of the difficulty avoided by the lightsaber.
Prior to entering this level, backtrack to 6-1 to get spark.
After jumping into the hole, move to the left a little bit to manipulate the position of the Flopper below. Use spark on the block and grab Shard 1, and then combine for lightsaber on the Fishbone in the next room. Swallowing above water is faster, and Kirby's horizontal speed with lightsaber out is always at running speed, even when walking or attacking. My strat for swinging through these enemies just makes sure that each Scarfy is killed with the Pupa before it.
The enemies in the next room can just be cleared with lightsaber. After dropping into the water, Shard 2 is hidden on the left.
At the beginning of the room, it turns out that sliding into the trigger for Adeleine's drawing is slower than just running up to it. Wait for the candy with the lightsaber out, then collect Shard 3 behind the Cutter barrier. In the last room, jump into the middle of the platform to avoid a slow walking animation.