Turns out Sonya Blade is a bland character, just like Kano.
Kano has never left his status quo. Where on the other hand you have characters like Scorpion, Sub-Zero, Raiden, Liu Kang, Kitana, even Johnny Cage and Jax Briggs... They all went through some character development, which lasted. They might return to their status quo sooner or later, but at least the NRS explored something new with them. Kano on the other hand? He is Sonya Blades bad guy. Always was and always will be.
That's not character development. That's not even a selling point.
No one cares about the comics. No one cares about the Black Dragon.
None of these two aspects (where Kano was bland as well) make Kano a good character with a great position in the Mortal Kombat universe. I'll write few things about Rain in a bit, but basically... It's IMPOSSIBLE to put more focus on Kano out of nowhere and have that actually feel meaningful, impactful and legit. Kano's position in the lore just doesn't matter to anyone, who is of any importance.
I'll skip the rest of your arguments, since I don't disagree with any of them. I'm not saying that Kano is a bad character. He is certainly better than your Sonya Blades and Cassie Cringes and Jacqui Briggses in my eyes. But I still don't think that he comes even close to someone like
our lord and savior Lord Rain:
Rain is a criminally underutilized character in the Mortal Kombat lore, even though there is just sooo much potential and intrigue behind him as a character.
Let's compare Rain to characters like Reptile and Kenshi, who are very well liked. Both Reptile and Kenshi have their things going on for them, but these things are very personal to them and fairly small in scale, when compared to the bigger picture. Reptile is constantly an underling, who searches for survivors of his race. Kenshi wants to avenge his dead wife and be a good father.
But Rain on the other hand?
1. Rain is the bastard son of a god, which makes him a demi-god and gives him far more power, than he was allowed to showcase so far in the games. He has lost to characters he shouldn't have lost for the sake of the plot (an annoying and on-going theme in NRS stories).
Rains powers (lightning, storms, rain and water, teleportation and enhanced healing) should make him a believable threat - especially when compared to more grounded characters like Kano. When Kano wins a fight he shouldn't have won, you blame NRS for being bad at writing power levels. When Rain wins, you just accept it, because he is a demi-god, who is as versatile as Raiden.
2. Rain is a narcissist, who is obsessed with power. He views himself as better than the rest. He wants to rule the rest. And that rest happens to be an entire realm called Edenia, which would affect Kitana, her future husbando Liu Kang, Sindel if she returns under a new status quo and pretty much the rest of the realm as well - since we know, that Rain wouldn't stop there. Rain would try to gain control over other realms as well. So what Rain wants and would do, would affect all the realms. There aren't many characters you can say the same about.
3. Rain has two half-brothers, who are more deserving of the throne than he is. Rain doesn't care about his family, so he wouldn't shy away from backstabbing them to death in order to get the throne. So you have some good drama right there.
On top of that even when Rain works for someone else, he is always planing ahead and trying to think of all the possibilities how he could get the most out of it. He had his own agendas and goals, when he was working for Shao Kahn and he had his own agendas and goals, when he was helping Mileena. Everything Rain does, he does it for Rain.
4. Rain is manipulative AF and always tries to get others to do what's best for him. We could see that, when he was pushing Mileenas buttons and trying to use her to get rid of Kotal Kahn for him.
5. He is a god damn ninja and everyone loves ninja characters in Mortal Kombat. On top of that he is the only ninja in MK (and in fiction?) with tons of bling bling and swagger. He beats you up and he looks good while doing so. Kano on the other hand has piss stains on his pants.
I legit don't understand how anyone can dislike Rain. To me that character is fascinating. You have this obsessively narcissistic character, who believes that he is a god and deserves to be worshipped. He wants more and more control and power, even if it's not rightfully his. He is still like: "
§$%& your rules and traditions and §$%& you too. I AM RAIN! I want what is rightfully mine and if you don't give it to me, I'm going to drown you in your sleep!"
