I actually didn't see eruki as someone arrogant. He's strong and I think he is also impressed with shirone. The two are having competetion with no hate.
Uh will he became a villain. Not exactly like a villain. More of the greed to defeat the villain and then in the end he was drowned by his own pain and he became a villain himself. I hope not
If that guy is not a jerk. I would be sorry for him. I know how painful it is to witness your dream being crashed. But since he's kinda jerk that might be a lesson for him. Great story looking forward for the next chapteeeer
Why did you rejected him