Yup! I honestly cannot see Brian and Ian as the same person/soul. They have similarities in their personalities but their experiences to that have been greatly different (especially with how Sol and his brother have approached/influenced him in this life). I treat Ian as his own complete person. Everyone, from my view, has mostly treated him either as an outcast for his powers or as Brian's stand in. I really can't get behind it. All it makes me do is miss and root for Ian more.
The author can still redeem this storyline as long as she does this well in S3 by having Ian remember his past life. It just depends on how she goes about it.
After reading another story about reunion that is slightly similar to this, I see why people have bad reactions to this manhwa. The pacing and structure of this story is not very well written. The author chose to first show us the present for 50 chapters and then immediately jump into the past and stay in the past for so long that people forget the present and more importantly the main character. With reincarnation/reunion stories, there has to be a good amount of jumping back and forth from the present to the past in order to keep readers interested AND informed of the entire context of the story. With how it is written right now, readers miss Ian and are unable to reconcile the fact that Ian and Brian are supposed to be the same person/soul.