11.5.0 Virus Dungeon »« 11.3.0 Talisman Dungeon
11.4.0You get the Lord of Light Dungeon Keys by playing level X of any Lord of Light in Time Rift
The dungeon opens for two hours and can be farmed.
Sands costs are steep.
Rewards include various awakening materials and 3* colourless evo runes, this is your primary source for awakening materials, so grindng it will be required.