On Sunday, Mortal Kombat Online invited fans to participate in a social media experiment called the Mortal Kombat: Royal Rumble. It combined hype from two of NetherRealm Studios' latest projects, including Royal Rumble sponsor: WWE Immortals!

Inspired by the annual WWE spectacle; the MKO event featured 30 randomly drawn kombatants, entering at regular intervals to fight for enduro supremacy. Shinnok was the last kombatant standing - buoyed by Twitter support, and fandom's hopes to see the fallen elder god return to prominence in Mortal Kombat X.

Many klassic characters received dedicated support from fans, but a few entrants left onlookers scratching their heads. A list of 85 kombatants was compiled for the draw, replicating the WWE tradition of surprise returns and unlikely upstarts with a few non-playable characters from MK past. Here's a refresher on some of the characters fans didn't recognize during the Royal Rumble:

#2 Kai
First Appearance: Mortal Kombat 4 (1997)
It was a little surprising to see some fans unsure of who our #2 entrant was. Kai has been close to a lot of Mortal Kombat X speculation over the past 12 months, inspired by the broad expectation that MK4 would provide a sequential base (for a new timeline).

It was that reasoning that boosted Kai to #3 on MK Online's Top 10 Kombatant Comebacks list for MKX. Alas, there have been no signs of the now fabled warrior, who was once the forebear for a new generation of warriors, which is now coming into focus.

Introduced as a former member of The White Lotus Society, he effectively replaced Kung Lao as friend and ally to MK4 hero - Liu Kang.
His background had him learning the martial arts from masters across Asia (and Kang himself), but his fighting style, and unique tribal markings gave every impression of more exotic origins. In his arcade ending [embedded above], he was gifted Raiden's lightning staff. A reward that seemed to only serve to aid in his aimless hiking. A return in Armageddon failed to give Kai the purpose or appearance of a warrior of significance. A disappointing end to a character who was almost a big deal.

Despite an underwhelming end; Kai continues to be regarded as a unique fighter with untapped potential. His original design begs for a full Zulu warrior revamp -- ditching pedestrian US origins for an intercontinental flavour missing from Earthrealm's defenders! In support, his trademark capoeira-styled handstand fighting seems perfect for embellishing the modern fighting mechanics, creating a unique fighter that finally gives Kai the presentation he deserves.

Mortal Kombat X Chances: We haven't given up on the possibility of Kai leading the new generation of kombatants in Mortal Kombat X. If comic book references to a "Netherrealm War" indeed reflect the MK4 plot of Shinnok's invasion -- Kai at least has a chance. That chance seems to be dwindling, and may ultimately be reduced to print, but any shot is better than none, at this point.

#3 Delia
First Appearance: Mortal Kombat: Armageddon (2006)
Emerging from non-playable obscurity, Delia was a more understandably baffling entrant into our Royal Rumble. Having never been depicted as much of a fighter, even in her few appearances, it was unsurprising that she was the first warrior eliminated, as well.

Delia was an Edenian prophet who foresaw the oncoming threat of Armageddon and created the elemental Blaze as a tool of stopping it. Aiding her in the elaborate prevention plot was husband Argus - a god, who fathered two sons with her: Taven and Daegon. These demigods were to have engaged in a contest of godly design, but Daegon was awoken early. corrupted, and set out to murder his parents, instead. So much for seeing the future, huh?

Delia's temple eventually became home to the Lin Kuei clan of Earthrealm. A legacy that gives her an undercurrent of importance, and connected Taven to the present-day Sub-Zero, Kuai Liang, who at that time had assumed the role of Grandmaster to a new incarnation of the clan.

Mortal Kombat X Chances: Given that Mortal Kombat (2011) reset the sequence of events at the point of the first game - we have to wonder what that did to Delia's vision of Armageddon. Daegon and his Red Dragon clan appear to be a force working within the comic books, which may mean Delia once again met a grizzly fate. That doesn't mean her legacy won't remain in tact, though.

#4 Khameleon
First Appearance: Mortal Kombat Trilogy (1996)
Khameleon holds the distinction of being the only console exclusive character from the main roster. She debuted in Nintedo 64 versions of MK Trilogy as an unlockable, grey palette swap of Kitana. By the time Armageddon applied the same all-in concept for the 3D era, Khameleon had missed the initial cut. This forced her only other appearance into later Nintendo Wii versions of the 2006 game [full story].

Despite exceptionally limited appearances, the cult of character has kept Khameleon well within the purview of MK fandom. The popularity of the N64 console in US markets helped expose the character to a broad base, but its the simple plot of her survival as a female member of Reptile's race that keeps her intriguing.

Mortal Kombat X Chances: In a game all about the next generation of fighters - few characters are as ready-made to play a part. The fate of the Saurian Raptors has long been a plot of interest, and finally following through on the coupling of Khameleon and Reptile, or the male Chameleon, would be exceptionally satisfying. Is the world ready for the repopulation of the reptile race? An Australian retail chain certainly seems to think so.

#11 Kia
First Appearance: Mortal Kombat Mythologies: Sub-Zero (1997)
Not to be confused with our #2 entrant (Kai), or #5 lookalike Sareena!
Kia is a demonic assassin who serves Quan Chi and the Brotherhood of Shadows. She's one of a trio who debuted in the Sub-Zero spin-off game (w/ Sareena and Jataaka), later returning to appear briefly as non-playable sub-bosses in Armageddon.

It may not be obvious at a glance, but Kia was first depicted by fan-favourite blonde bombshell Kerri Hoskins -- better known for her portrayal as the second Sonya Blade, in MK3. Mythologies was the final major Mortal Kombat release to feature digitized actors as game sprites, succumbing to the mid-nineties onset of polygons. This left the game to a certain amount of obscurity, but Kia can credit her anonymity to being overshadowed by her teammates.

Tortured would-be hero of the group Sareena was the unmistakable breakout star. She had flirtations with both Sub-Zero brothers, managed return playable appearances in in a portable version of Deadly Alliance (Tournament Edition) and Armageddon, and was on her way to being knitted into contemporary plotlines before the 2011 reboot.

Mortal Kombat X Chances: We know Quan Chi will lead an army for an unspecified plot, and that there's a "Netherrealm War" at some stage. Who better to serve the evil sorcerer than his trusted demon assassins?As the backstory and rival to a more in-demand character (Sareena), Kia's fate is always subject to use, but as an old character we haven't seen a lot of, she and Jataaka are ripe for a playable revamp. We don't fancy her chances, but hope to see a cameo, or comic book role, at the very least.

#13 Wu Lae
First Appearance: Mortal Kombat: Armageddon (2006)
You may remember Wu Lae from Mortal Kombat Online's 2012 April Fool, but the character's true origins lie in Armageddon's Konquest Mode.

Wu Lae was a non-playable sub-boss battled in the snowy regions of Arctika, where his Tengu clan occupies adjacent territory to the rival Lin Kuei. Through the course of the Konquest action-adventure mode, it's learned the Tengu encountered Noob Saibot & Smoke before briefly battling demigod Taven.

Wu Lae is perhaps most memorable for his interesting design. Covered head-to-toe, with a full face mask, there's enough visual appeal to the character to give him at least a notable percentage of the Boba Fett style mystique. There's not much more to the character, but his minor established connections and stand-out appearance could always warrant another look.

Mortal Kombat X Chances: If the heroes of Earthrealm had remained dead after the massacre of Mortal Kombat (2011) - a character like Wu Lae may have warranted another look. As it stands, his best chance of a return is probably as canon fodder for the fatality fixated comic book series.

Ow! My balls!

#22 Mokap
First Appearance: Mortal Kombat: Deadly Alliance (2002)
Most major fighting game franchises have joke characters. Mokap is Mortal Kombat's most deliberate. This makes him a sometimes controversial figure, despite a fantastic gameplay experience in his debut appearance as a hidden unlockable fighter in Deadly Alliance, and relative unimportance.

Mokap tooled around in Deception's Konquest Mode -- an inviting prospect for the punch option -- and returned for a final playable appearance in Armageddon. He came and went with few significant moments, perhaps best remembered for motion capture/testicle puns. He's a rendered tribute to motion capture artist and series actor Carlos Pesina. That's about all you need to know.

Mortal Kombat X Chances: Before you throw the Mokap out with the bath water, there's still some fun to be had. We don't see Mokap as an in-game character -- the tone of MKX seems too serious for that. Where he might find a good run is as a background presence in the comic books. Where there's a film set and a Johnny Cage - there's always room for a Mokap. Why not a done-in-one comedy chapter that gives us the long awaited dream match between Mokap and MK2011 extra Stuntman? The punchline: Johnny Cage does his own stunts - no CG required!

There are many more characters still toiling in obscurity. Register to go to school and talk about the old favourites in the 3D Kombat Klassics forum! Speculate about what's coming next by diving into the forum for Mortal Kombat X!