Korean Manga/Novel spoilers

I Have Become The Hero's Rival

Well Currently manga has updated 26 chapters so I will just give spoiler about what happen after that...

As far we have seen On the day of Felix’s funeral, MC was pretending to cry and whispered to the heroine if she can act.The heroine told MC not worry and punched the crown prince(1 of the 3 male leads) and started cursing him and crying.Instead of being angry, the crown prince was elated that the heroine was focusing on him.
MC used a chance and met the crown prince’s younger brother and persuaded him to cooperate and help them.
***
MC took the heroine and Felix to an island to find a special type of spirits that can stay in the human world so that the heroine can contract that spirit.The heroine succeeded.
What MC didn’t know was that in order to protect MC, Felix let the devil eat some of his soul which caused him to lose all his feelings except his love towards MC.
(Note, because of the devil, Felix couldn’t use magic anymore).

That love was no longer love, it was an obsession.He was afraid of what he might do if he stays so he decided to leave. He went to the sea with MC and carried her to a rock inside the water and left.MC stopped him.
Felix forcibly kissed her and then asked her if she can really bear him.
MC was frozen and started crying as Felix left.
(What I didn’t mention was that the devil, affected by Felix’s feeling, started to fall in love with MC. When the devil eat some of Felix’s soul, he managed to temporary take control of his body in order to protect MC. He talked to MC and told her not to smile since his heart hurts when she smiles. When MC cried after realizing that he was the devil, he told MC not to cry since his heart hurts more when she does.)
***
I think 2 years passed?
During this time, MC practiced making potions and was unexpectedly very talented in this area.
The crown prince became the emperor and he was war crazy.
There was a war hero from a commoner background.
When MC saw him first saw him, she recognized him as Felix even though he looked completely deferent from head to toe.
After some threatening, she managed to drag him home and had her first time with him(she used a lot of healing potions and still had a few rips broken when she woke up).
Because of the devil’s influence, Felix’s body became abnormally strong and his appearance and even hair color changed.
Now, the devil swallowed 50% of Felix’s soul.
They now switch control over his body every 12 hours.
***
Felix became the emperor(who was the crown prince)’s guard.
MC made a new plan.
She started making music and novels she knew in her past life.A musician asked MC what name to use as the composer.
MC: Beethoven.
A novelist that was writing a novel asked MC what to write as the author’s name.
MC: Shakespeare.
MC felt guilty and apologized to the real authors in her heart every time.
***
Because of MC’s scheme, The emperor started ignoring Benjamin. Benjamin started investigating the new artists and somehow figured out what MC was planning and only said “cute”.
***
Benjamin went to see MC with a bag in his hand.
MC stiffened because of the words written on the bag.
It was Mozzarella(which is similar to “Mozart”, one of the name she used), he was indirectly telling her that he knew she was the author for all the new arts that came recently. MC felt weirded because Benjamin was acting and saying strange things. After he left, when MC talked with the heroine, the heroine said that Benjamin was looking at MC with eyes similar to how he used to look at her. MC didn’t immediately realize that Benjamin was in love with her because of the pure affection the heroine and Felix gave her.
At the realization of Benjamin’s feelings, she felt goosebumps.
***
At a national day, MC used a potion to turn herself into a man. She sneaked in a church after she drank an invisibility potion.Inside, she was shocked to see Benjamin with something black flying behind him. Benjamin seemed to have heard her and immediately moved his hands across the wall looking if there was someone there.
As he was about to touch MC, the black thing said they are going to be late. Benjamin gave up and left.
(Honestly, I don’t remember why she sneaked here or what her scheme was for).
MC realized that Benjamin somehow summoned a devil.
She quickly ran outside and continued to run. Suddenly, she realized that she was running in circles. In other words, Benjamin used the devil to make her run in circles.
MC suddenly lost consciousness.
***
When she woke up, she was inside a place like a prison cell. She was tied to bed with chains. Looking across the iron poles, she saw Benjamin sitting there, watching her.
MC was terrified, she wanted to pretend to be Shakespeare but gave up when Benjamin said he had no reason to keep her alive if she wasn’t Irene Amber.
He explained that he wasn’t the one who summoned the devil.
He made the emperor’s younger brother take drugs and forced him to summon a dream devil, a strong devil that eats the summer’s dreams by making the summer sleep forever and the summoner must hand the right to order the devil to someone else.