Phantom Blade Zero

Perfect (true) ending - "The Final Battle":
The tasks can be done in any order, but all of them must be finished before you pass the "last chance to get things done" warning near the finale.

1. Crystal Puppet Eyes:
Complete the optional Mountain of Imprisonment region to get the Crystal Puppet Eye [Yin].
Defeat the hidden boss in the Crimson Manor (Weeping Creek Valley) to get the Crystal Puppet Eye [Yang].

2. The four Acolyte bosses:
Interact with the four scarecrows in Village of Lu, Pangzhen, Meigu Lake and Crimson Manor and defeat each Acolyte boss.
You get Yanru's Blazing Mask (fire), Leiting's Thunder Mask (lightning), Guhe's Venom Mask (poison) and Hansui's Frost Mask (ice).

3. The mirror at Meigu Lake:
With all four masks, sail the Sha-Chi boat to the west side of Meigu Lake (near the ice floes and the snow-covered mountain).
Find the mirror and enter the secret realm. Defeat the boss there, then insert both Crystal Puppet Eyes into the statue.
This also gives you the Phantom Edges Flying Dagger and Goldblaze.

4. Five Long Pillars:
Four are in Weeping Creek Valley, Crimson Forest, Meigu Lake and the mirror realm. The fifth is in the finale area.

5. Serpent items:
Collect the White Serpent Eye, the Black Serpent Fang and the Red Serpent Tongue.

6. Quick Hand Zhang's Relics:
Meet Quick Hand Zhang five times in five regions. Each time, find three Relics in green-glowing treasure chests.

Finish the game to see the perfect ending, "The Final Battle".