Mortal Kombat 11 Ultimate Bundle is now available on Steam as an add-on for the Windows edition of Mortal Kombat 11. This includes Kombat Pack 2, which is also available separately, adding three new fighters, Mileena, Rain, and Rambo, the latter of which features the voice and image of Sylvester Stallone. This announcement has all the details, and here's a summary:

Mortal Kombat 11 Ultimate is available now featuring all 37 playable fighters, story content and game modes, including:

• Kombat Pack 2 – Newly added fighters Mileena, the hybrid Tarkatan and Edenian evil clone of Kitana; Rain, the royal Edenian demigod; and Rambo, the iconic Special Forces soldier featuring the voice and likeness of actor Sylvester Stallone, along with character skins inspired by the “First Blood,” “Rambo: First Blood Part II” and “Rambo III” films.
• Mortal Kombat 11: Aftermath Expansion – Franchise-first story expansion continuing the epic narrative from the main game, three playable characters incl. Fujin, Sheeva and RoboCop – and 10 additional character skins.
• Kombat Pack 1 – Six playable characters incl. Shang Tsung, Nightwolf, Sindel, The Joker, Terminator T-800 and Spawn and 25 additional character skins.