Rune of the Duelist Indomitable
From Dota 2 Wiki
|Rune of the Duelist Indomitable|
|Gem / Rune|
Adding this gem to an item will enable that item to track Legion Commander's successful duels, with a special effect displayed upon victory.
If the gem is placed in a socket in another item, it behaves just like a normal tracking gem. The win count effect is not displayed.