Cryptic Chasm

Dungeon Parts
In this dungeon, after Floor 30, there is a fake exit that says the following within 6 different slates. There are Unown stones that are on floors: 1, 5, 10, 15, 20, 25. It's recommended to pick them up to progress the dungeon.
 * 1) If this is where you ended then you took a false path.
 * 2) Below the center of obscurity lies the key.
 * 3) If you are unknown of origin, then that is all you need to know.
 * 4) By dawn, you must swim the seas. But by dusk, you must walk on land.
 * 5) An odd past awaits you.
 * 6) Ahead lies a creature of unimaginable power

Pokemon
''Pokemon in bold are recruitable. Please visit the Recruitable Pokemon page for more information.''
 * Woobat (3%, 15-40F)
 * Sigilyph (-2%, 30-40F)
 * Klink (1%, 40-50F)
 * Elgyem (-3%, 56-60F)

Boss
The boss at the end is Mewtwo. Before the battle, Mewtwo appears, and he says that the chasm was disturbed by the player. After explaining some things, he challenges the player. After his defeat, he then explains some more things to the player, and then erases the player's memories of Mewtwo. Mewtwo then bids the player farewell. Some lines spoken by Mewtwo are references to Pokemon movies Mewtwo Strikes Back and Mewtwo Returns.
 * Mewtwo

Mystery Eggs

 * Cacnea
 * Mawile
 * Sneasel
 * Sableye
 * Spoink
 * Gligar
 * Drifloon (30-40F)

Dungeon Objective
The final boss has a rare chance of dropping Golden Mask.

Rules

 * On floors 1, 5, 10, 15, 20, and 25, there will be stones that spell O-R-I-G-I-N respectively. You must have these stones to open a door on Floor 30. Note however the door on Floor 30 has a 99 % chance to spawn.
 * There is a maze puzzle on Floor 15. On the bottom right, there is a small room that leads to keys needed to open sealed chambers on Floor 30 and 50. You must have Dig to dig up these keys.
 * Bring a water (Dawn/Day) or ground (Dusk/Night) type Pokémon. These Pokémon are needed to pass Floor 40.
 * Have the Engraved Tablet in your bag to open the final locked door on Floor 50.

Tips

 * Do not enter the regular stairs on floor 30F. There's a sealed room that can be unlocked on Floor 30 with one of the Enigmatic Keys and O-R-I-G-I-N Stones.
 * Have a water/ground Pokémon such as Barboach or Wooper for Floor 40 to progress.