it might not be an imagination i remember that was stuck on his leg was he was experiencing and now we saw a scar in his leg so here is my theory when ever he is on scene he enters some world where the scene hes doing is real so i think what he does in that world affect his so u could say his soul left his body and went inside a duplicate but the scene is so if he's hurt in the other world it leaves a scar. so basically, mc's soul leaves his real body and enter in and out of different dimension
but its leaving a burden in his actual body ( hope you understand my theory :)
it might not be an imagination i remember that an object was stuck on his leg when he was experiencing weird things and now we saw a scar in his leg so here is my theory when ever he is on scene he enters some world where the scene hes doing is real so i think what he does in that world affect his so u could say his soul left his body and went inside a duplicate but the scene is so if he's hurt in the other world it leaves a scar. so basically, mc's soul leaves his real body and enter in and out of different dimension
but its leaving a burden in his actual body ( hope you understand my theory :)
I think he is just mentally sick and the experiences he had was just his imagination coz remember on chapter 3 he was heading to the hospital but he hesitated and said forget the hospital (I'm not sure if what I said is right but let's just see how it goes)