Kronika was the worst villain in MK history. On top of that, she was supposedly the boss, but ended up weaker than MK4 Shinnok. They did an excellent job revamping Shinnok and making him more formidable in MKX only to have him defeated by Johnny and Cassie.
Kronika was not needed. She was never mentioned in previous MK stories. She pops up in MK11 as Shinnok's mother and brings along his sister, Cetrion. Cetrion had more of a purpose as it could be argued that she is the elder god that Raiden has been consulting.
The story was more interesting when it looked like MKX set up Dark Raiden to be preemptively waging war against realms that posed a threat to Earth Realm. Liu Kang and Kitana seemed to be the perfect antagonists as they still wanted revenge on Raiden as they blamed him for their demise.
Story would have been better with Raiden taking out Liu Kang and Kitana's Netherrealm armies leaving them vulnerable. Instead of Kronika appearing out of nowhere, Liu Kang, having learned the secrets of the Netherrealm, finds the keep and wishes to harness its power to erase Raiden from history and reshape history as he sees fit especially the fates of he and Kitana.
In weilding the power, he incidentally brings back warriors from the past including his and Kitana's past selves. Thereafter, revenant Kang and Kitana lead the revanants and Noob Saibot to find the Jensei to empower the hourglass and the crown of souls. Same thing as Kronika, but without having to create a whole new character in Kronika to carry out the same objective. It also defeats the purpose in having a "titan" of a boss especially if closing out a trilogy of events. Why introduce such a huge boss of a character?
Revanent Liu Kang was severely underused. He claimed to have mastered Shang Tsung's sorcery as evident when he took his own soul and he also weilded an amulet when capturing Fujin, Nightwolf, and Shang Tsung. Him being the main villain in MK11 would've been dope. There was so much they could've done with him including set the stage for Onaga (dragon king).
Also,
For it to be Mortal Kombat, the fight scenes in story mode aren't as gory and we never see the characters use the full extent of their powers. This would be the perfect stage to show off the characters. Yes, its dope to pull off the special moves in arcade mode and online, but what about the story? It was lame to see Kitana face off against Shao Kahn only for her to slash his face blinding him. Where was the fan lift, fan toss, her other abilities?
I would have loved to see revanant Kitana and Liu Kang leading Nether Realm armies against Outworld and taking them out. Even when Special Forces invaded Shinnok's Bone Temple, there should have been some severe injuries and/or other casualties besides Sonya sacrificing herself. Would have loved an epic fight scene of revenant Kitana and Liu Kang completely obliterating Shao Kahn.
Also, there should have been an epic battle between Noob Saibot and Hanzo. Another battle with Noob fighting Scorpion and one with Noob against Sub Zero. He should have taken out 2/3 of them. As he claims final victory, he attempts to turn everything to utter darkness and he's stopped by one of them.
It would have been dope to see revenant Liu and Kitana, past Liu and Kitana, and Dark Raiden as the last ones standing at the end of story mode. They could still have Dark Raiden merge with Liu Kang (after he steals his own soul as well as the other souls of dead warriors killed at the hands of his Netherlands Realm armies). Being the last ones left Dark Raiden and revanant Liu Kang face off in an epic battle. The elder gods intervene, but Dark Raiden, revanant Liu join forces. Liu Kang uses his powers to merge revanant Kitana with her past normal self. The three of them face off against the elder gods and defeat them. Then Dark Raiden faces off against Liu Kang and Kitana. He defeats Kitana, and if need be, they could then introduce Kronika, a titan, to stop Raiden and Liu Kang. At this point, Dark Raiden and Liu Kang merge and take out Kronika. Fujin, Nightwolf, and Shang Tsung are freed from the void as the newly formed fire god Liu Kang attempts to reshape history via the hour glass.