"Injustice: Gods Among Us" proved to be a massive success for NetherRealm Studios, the same studio behind the "Mortal Kombat" games. A proper sequel, "Injustice 2," is scheduled for release in 2017, and now, director Ed Boon teases both Sub-Zero and Spawn as the most likely characters that will be added via DLC.

Announcing on Twitter, he revealed the poll results for the most probable "Mortal Kombat" character that would guest in the game. Sub-Zero led the poll with 52 percent, followed by Johnny Cage with 23 percent, Raiden with 20 percent, and lastly, Jax with 5 percent.

In a separate post, Ed Boon then revealed the results of the poll regarding a non-"Mortal Kombat" guest character. Spawn was on top of this poll, with 48 percent. Hellboy took the second spot with 21 percent, followed by Buffy at 19 percent, and lastly, the Terminator at 15 percent.

He also revealed that more than 30,000 people had voted for Spawn and over 20,000 fans had voted for Sub-Zero.

According to Screen Rant, Spawn had appeared in the "Mortal Kombat" franchise before, and Sub-Zero did appear in a DC fighting game also developed by Ed Boon before, "Mortal Kombat vs DC Universe." However, this would be the first time they will interact directly in the "Injustice" timeline, where the Joker's actions caused Superman and other heroes to lead a dictatorship over Earth.

Spawn, created by comic book creator Todd McFarlane, rose to popularity in the 1990s and became known as one of the darkest comic book heroes to date. A reboot film has been in development for the past few years but has not yet entered production.

The character Sub-Zero has been a big part of the "Mortal Kombat" series since the very first game. His Fatality, which saw him rip out the spine of his opponent, became a subject of controversy and was a reason why the Entertainment Software Rating Board or ESRB was created.