Mortal Kombat Villains Who I Felt Had Interesting Concepts But Didn't Get Their Potential Fleshed Out

Here's a list of Mortal Kombat villains who I felt were pretty interesting but didn't get their potential fleshed out.

Kintaro

Kintaro was introduced in Mortal Kombat II as Goro's stronger replacement. I'd agree he's really that difficult in the second game. His plotline was where he replaced Goro as Shao Kahn's new general and is said to be more powerful and agile than his predecessor. 

He returned in Mortal Kombat Trilogy as a playable boss character and sometimes took over Motaro's slot. But after Trilogy, he simply faded away into obscurity/ There some unproven rumor suggested that he was vaporized by Raiden but was proven false by MK: Deception. In Shaolin Monks, he's merely introduced only to be killed off by Liu Kang and Kung Lao. 

During Armageddon, he was seen part of the Army of Darkness but his storyline wasn't even expanded for somebody who's even more powerful than Goro. I felt like the non-canon Malibu Comics had given more personality than he was in the games. Mortal Kombat X later showed him to die in quite the dumbest way possible where a possessed Sonya Blade uprooted his head. I guess even with his strength, Goro is still that beloved Shokan over him.

Shinnok

Shinnok for me had some interesting potential. He's the ruler of the Netherrealm but I guess nobody really cared too much about him in Netherrealm Studios. At first, he's presented as that fallen Elder God who Raiden banished after thousands of years of battle. He's more of a sinister version of Loki and supposedly more powerful than Shao Kahn. 

In Mortal Kombat 4, I felt like he's just a lazy Shang Tsung then he returned to Armageddon with his own personality but not even enough fleshing out. I guess Netherrealm gives too much favoritism for Shao Kahn. He later showed he's just lazy by letting his clone lead the Forces of Darkness which really WTF. In the reincarnation of the series, he manipulated the events which was a plus but his role would later end up getting watered down. 

By Mortal Kombat X, he returns with that creepy-looking Corrupted Shinnok form as an NPC. I felt even his storyline there wasn't done properly. I felt like Cassie and Johnny beating him after being "greened up" was another dirty finger to his character. Worse, making Liu Kang and Kitana replace him after he's just a living head (not a good way to write him off in contrast to Shao Kahn's badass defeat) might be a reference to somebody got fired from Netherrealm Studios. Quan Chi had better development than this guy. 

Overall, I felt like he's more of Mortal Kombat's version of Loki considering he's Raiden's arch-rival.

Onaga

Onaga is supposedly the emperor prior to Shao Kahn. He exists as the dreaded legendary Dragon King who was predicted to return one day to reclaim his throne. Shao Kahn was wise enough to poison him first before getting rid of him. Then he appeared as a cooler version of Gargos from Killer Instinct 2/Gold where he manipulated Shujinko into getting the Six Kamidogu allowing his return. I felt like they should have made this guy more threatening than his usurper. 

For all the cool factor I felt he had - he wasn't given much development either. In Deception, he's beaten by an aged man's rage which is really stupid. I felt like Scorpion beating him off would have been much better or Zombie Liu Kang destroying him. 

By Armageddon, his storyline even gets more pitifully played down where he's forced to join an alliance with his usurper Shao Kahn, Shang Tsung and Quan Chi. Although he does get even with Shao Kahn at the beginning but when Taven's victory resulted to a third unexpected outcome, well he's still beaten again by Shao Kahn.