Void Spirit was released as part of the Outlanders patch on Tuesday, November 26th, 2019.
Void Spirit - what we knew before the release date
The hero teaser shows a mysterious, long-haired, seemingly-omniscient Celestial whose face is yet to be revealed, who speaks of a forecoming "Great Confluence" and that he must fray into the mortal realm to join and prepare his other Celestial brothers for this foretold event. The teaser symbolically affirmed at the end that the aforementioned Celestial brothers are Earth, Ember, and Storm Spirit.
The teaser also revealed possible glimpses into the hero's ability and weapon of choice: a two handed blade. Possible abilities that can be incurred from the teaser involve a vision-creating ability that allows him to look into other heroes and summoning portals that can transport him into other places.
We could expect Void Spirit to have similar characteristics to his pre-existing brothers--a high-difficulty, mobile hero with a mastery over the elements. All the current Spirit heroes also have the ability to create elemental Remnants (possibly this vision-creating ability?) and the ability to turn into a ball to achieve their signature mobility, although this assumption conflicts with the portal-making ability shown in the trailer.
While the first question that comes to mind involving a new heroes are its role and abilities, another thought-provoking mystery is the hero's main Attribute, since the three existing Spirit heroes have balancely filled the three Attributes, with Earth Spirit being a Strength hero, Ember Spirit being an Agility hero, and Storm Spirit being an Intelligence hero. So what main attribute will this off-balancing newcomer possess?
With the mystery surrounding the hero's face and the fact that the hero is called Void Spirit, one also couldn't help but wonder if the hero is also related to Faceless Void, and if the realm he cometh from in the trailer is the same as where Faceless Void comes from--Claszureme. Although the hero comes with so much ambiguity, one thing that's for sure is that Dota 2 fans will be eagerly waiting for his arrival and can't wait for him to be finally playable in the game.
Update: Snapfire will be released together with Void Spirit on the Outlanders Update. The two heroes will also be available soon in Underlords. And Void Spirit's face is finally revealed.