Here is the full list of all 20 Legendary Mahjong achievements.
Match 10 Ice Tiles.
Restore the Temple of Water.
Unlock the Celestial Gate.
Restore the Temple of Time.
Restore the Temple of Wisdom.
Get the highest rank.
Restore the Temple of Earth.
Use 10 Whirlwind Tiles.
Undo 100 moves.
Match 10000 tiles.
Restart 5 times.
Open 10 Box Tiles.
Restore the Temple of Fire.
Use 10 Magnet Tiles.
Match 10 Lock Tiles.
Get a new rank.
Match the first 2 tiles.
Restore the Temple of Air.
Restore all the temples.
Complete all levels in all the temples.