ABANDONED. Parallel world of knights and kings

[Dragonslayer]

I remember the main plot but i don't remember the title, maybe someone else might. Here is the story i remember
Warning Spoilers ahead:
*main character is an outcast who looks up to his best friend
*Reads a story about a king who chooses one of his subjects to serves as his protector and second in command( either a sentinel or paladin). however the Sentinel becomes jealous of being second and tries to pull a coup on the king and manages to kill him, However the king returns as a spirit and his throne becomes untouchable to the sentinel.
*the main character learns that the world is real and is able to travel there by his grandfathers advice.
*The main character starts his training to become a knight and starts to crush on one of the female knights
*Other details he learns during his time is that everyone's eye color determines whether someone serves the previous king, the enemy, or neutral, and that everyone in this world is connected to someone in the main characters world( where if someone dies here, their doppelganger dies as well).
*After completing his training, the boy is knighted and given a sword similar to his commanding officers
* He and his companions then leave on a quest to stop the sentinel's forces which results in his Commanding officer's death halfway( who is then revealed to be the main character's grandfather's counterpart).
*Before death, his commanding officer gave the MC his sword and to seek out a monster who owes him a favor.
*The MC finds her but before he can explain is forced to take the monsters test( simple travel through a maze and ignore all temptations along the way)
*Even though he fails the monster agrees to assist him when she notices he is carrying his commanding officer's sword.
*The MC comes up with a plan to beat the enemy soilders and the monsters makes a meal out them
*The MC prepares to return home as his job is done for now and kisses the female knight promising to find her counterpart in the real world.
* back in the real world he learns that his grandfather died from a heart attack and his best friend has somehow been affected by the sentinel
Does anyone know this book or nove( Young adult at best

[Rainbowheart]

When did you read it?

[Dragonslayer]

about a couple years ago

[Rainbowheart]

How old are the main characters? Are they teenagers?

I know you mentioned you thought it was YA.

[Kris]

No response, moving to Abandoned folder.

Dragonslayer (OP) was last active on the site in December 2019.