Ember Spirit, as well as Brewmaster, Storm Spirit and Earth Spirit, were Pandaren in DotA. They were remade to avoid copyright conflicts with Blizzard, as the Pandaren are a race in the World of Warcraft.
Most Ember Spirit lines are only 4 words long. Zin says about himself: "Four words is plenty.".
A pair of relic Divine Rapiers were kept in the Fortress of Rogue Flame, and when Sin took them back to himself, they showed their true power.