Boy Goes to Mirror/Alternate Reality With Changing Eye Colors

[kkinkin23]

Hello! So like everyone else on here there was a book I loved but forgot! So if you could help that would be wonderful! I'll try my best to be descriptive as possible!

The story is about this boy who goes to this alternate universe that mirrors ours, but the mirrored one is back in medieval times. I remember everyone had either green (undecided sides) blue (good) or red (bad) eyes and that there was a part in the second book where a girl convinced another girl to become good and saw her eyes change from green to blue.

The boy finds out his grandfather from his time is actually a tough commander type in the alternate universe and that his father is like a king of the undecided people? The grandfather/commander sacrifices himself to save the boy and when the boy comes back to our universe his mother tells him his grandfather died of a heart attack or something. Also when he dies in the alternate universe the king of undecided people (boys father commanders son?) he changes to blue and in real world the says he had to pull over his car and that he started crying over his dad's death or something???

I remember the boy was with a group of solders and one of them was named Helix or Felix? I think his weapon was an axe and he may have had a red beard?

 Also! I remember this very clearly! At one point the boy and solders were camping and the boy saw a lot of lights which he thought were the enemy. He started screaming and waking everyone up and all the men mounted for battle. Then they found out it was only fireflies or some strange animal from there universe and they all laughed and the boy felt silly.

Also! The boy heard one of the men get up and go to the bathroom and I believe the boy thought something along the lines of "in stories you never read about people who have to go to the bathroom" ANYWAYS not super important what is important is, is the fact that the man who got up to "go to the bathroom" was really working for the enemy and everyone was confused as to how he faked his eye color.

In the second book when the boy is back home he is thinking of this girl he met in the other universe and is looking for her earth duplicate when he becomes friends with this other girl. This girl is really tough and likes karate and fencing and such and when practicing her hair catches the sunlight and turns it red (she dyed her hair) and the boy finds out SHE is the counterpart of the other girl. She also hits him in the face since they were fencing (I think)

THIS new girl goes to alternate reality and like the boy has to pass this test. Her test is to ride a horse and get all the rings on her lance I believe. She thinks her opponent won, but he missed one so she won. Her opponent says something about how he lost to the boy first and now to her.

Hopefully someone can help! Thanks!