Conclusion
-Hacking Skill- Monika: Manipulating chr files on an obvious character folder, script manipulation and Save/Load Manipulation one by one, she herself admits she is not good with Doki Doki's coding.
Miyuki: Modified the entire universe and all of its timelines on her phone showing inmense if not superhuman skill with hacking, also chsnging the HUD, Save/Load functions, Time manipulation, script and has shown expertize on the code of Kimi to Kanojo, alongisde the nature of visual novels.
Miyuki wins
-Physical Combat- OP states they are in the same room and Miyuki is equipped with her metal bat.
Miyuki has experience with beating people to death, like the MC, his cat and Aoi, has praticed Baseball and is a member of the track team.
Speed equalized in OP, so speed is meaningless.
Monika has no weapons nor any remarkable physical combat skills to counter Miyuki's overwhelming superiority in this aspect. Proof:
https://youtu.be/oXcwYgoGR0E (at 5:37) Winner: Miyuki
-4th Wall Awareness- Miyuki has knowledge of the internet, other NitroPlus Games, the nature of Visual Novels and other timelines where the MC does not chose her, know the concept of censorship saying Aoi's mutilated body would have to be censored to keep the game from being categorized as Gore, was self aware well before the twist happened, and can aknoledge the passing of time in the real world. Proof:
https://youtu.be/Zq3C942zSTM (passing of time)
https://youtu.be/oXcwYgoGR0E (Miyuki about censorship of Aoi's body 7:50)
Monika doesnt know what Super Smash Bros is, no knowledge of the real world, which is why she asks you several questionsabout it, Twitter Monika has been ruled out, only sentient with Club President status. (Proven by the fact Sayori gainst sentience by gaining the club president title in the Deleting Monika, Bad Ending and True Ending of Doki Doki) Proof:
https://youtu.be/4MJNwp3AEJk (7:31)
https://youtu.be/9Plqx5LKfsQ (Deleting Monika early Ending) Winner: Miyuki
-Resistance to Player Intervention- Monika can be hurt by the player by simply deleting her character file and make her lose power over the game itself in both the bad end true endings.
https://youtu.be/EqnVcucve3k (4:09)
Miyuki cannot be stopped by the player alone, you need to call NitroPlus in japan with your purchse number to have the choice between having Miyuki kill Aoi from existence or viseversa.
Winner: Miyuki
-AP and Confirmed Feats- As mentioned above, Miyuki can kill and erase Aoi (Her exact equal with the powers of "God") and viseversa from the past and even MC-kun's memories. Proof:
https://youtu.be/ZD5OWrdYxrQ (Miyuki True End)
https://youtu.be/8Vh09QUZdiY (Aoi True End)
While Monika cannnot fully destroy Sayori with the club president powers, making her her equal in all powers, AP and Durability even on her Bad ending "erased" state, only able to damaage the script in the progress while Sayori's file stays intanct thru the entire "battle". Proof:
https://youtu.be/rcVJyI3lP5M (17:25 onwards)
Winner : Miyuki
Q&A -But Miyuki's powers come from God!- The universal scale coding was already made before God applied the changes to the game, afterwards she still keeps all of the powers shown above.
Think it like Kyubey giving Madoka her Goddess form, explained above in higher detail
-But Monika is inmune to all erasure!-
She has only shown durability to people deleting her character file, not to other ways of reality warping/Hacking, like Miyuki does, who has knowledge of how visual novel games are coded and has a 100% understanding on how her own game is coded, while the same is not true for Monika, making her have a major disadvantage in terms of a neutral hacking battle.
-But Monika has a twitter! She is above the game and absolutely nothing can hurt her!-
Not only she shows different expresions and worries as her game version, Twitter Monika has absolute free will to tweet wathdver at any time, while the game monika has no knowledge of basic social structures or elements outside of her own game like Miyuki does.
Not to mention her twitter was made by somebody else, as she herself states.
-Scenario 1, Doki Doki Monika vs Doki Doki Miyuki -
Code:
stalemate since Monika cant fully delete someone of her own powers as shown in the bad ending and reasons above.
-Scenario 2: Kimi to Kanojo Monika vs KtK Miyuki-
Miyuki wins by putting Monika in a game's code she doesnt know and hell, remember how Monika is a novice at game hacking? Miyuki deletes Monika just like she could do with Aoi.
-Scenario 3: Neutral Space Miyuki is coded into Kimi to Kanojo and Monika is coded into Doki Doki, then Miyuki wins by expertize and her code is far more secure than Monika's. (Thousands of lines of code vs chr file. (Plotwise, of course) ), and reasons above. Monika not being good at coding and not knowing about the real world will seriously affect her against someone who is adept at it, but even worse, Miyuki has been sentient from the beggining and know about the nature of visual novels and even talks about other nitroplus games, which alongside her FAR superior physical prowess makes this match a sure win for Miyuki.