For the past few months, promotion for Injustice 2 has been curiously limited for a NetherRealm Studios fighting game. We expect to hear much more in the new year, but Creative Director Ed Boon may be dangling at least one cryptic clue to ponder over the holidays.

The tweet references lyrics from a 1973 educational song: My Hero Zero. Part of the Schoolhouse Rock! series, it was written and performed by Bob Dorough. The song in question sings the praises of the digit 0, as well as the powers of 10.

It wouldn't be the first time a song hinted at something from an upcoming game, but poor Uncle Ed can't tweet many things without eliciting a blizzard of requests, assumptions, and theories. Indeed, the reference could be something as simple as the weather -- which dipped to a reported low of 1° in Chicago, on December 15th. Close to zero, in some areas.

Then again, there is at least some basis for reading into Boon's message. The Creative Director was quick to acknowledge the likelihood of guest fighters in Injustice 2, making a recent polling of fans one of the more substantial talking points of the last few months.

Sub-Zero emerged as an overwhelming fan favourite, also deemed the most obvious choice in MK Online's earlier wish list ranking of Top 10 Guest Kombatants.

When Scorpion crossed over as a downloadable guest in Gods Among Us, he received a DC Universe makeover from celebrated artist and publisher Jim Lee. It wouldn't be unreasonable to expect something similar for the next Mortal Kombat guest, which may go further to answering the musical question: "How can Zero be a hero?"

In an arcade ending from Mortal Kombat versus DC Universe [pictured above]; Sub-Zero left the Lin Kuei to become a Batman-inspired vigilante.

This caped version of the ice warrior featured on MK Online's Top 10 Klassic Skins we would've liked to see in Mortal Kombat X. A return in Injustice 2, however, would arguably be an even better way to bridge the gap to the maligned 2008 crossover! Yeah, Super-Hero Sub-Zero is a wonderful thing.

[Related Article: Future Mortal Kombat vs DC Universe Sequel Unlikely]

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