From Dota 2 Wiki
Raigor Stonehoof's monolith draws it's power from the rays of the sun and the moon, imbuing it with the energy to counter the creeping corruption of Dire forces. Forged by a secret order of Nishai weapon smiths, it's a formidable armament feared by those who dwell in the shadows.
This item was the $185,000 stretch goal for the ESL One Frankfurt 2014 bundle. After community feedback, the stretch goals were altered and the item was released for all ESL One Frankfurt 2014 Compendium owners.