It would not leave me alone
Okay so what is Rei wasn’t talking about Enji when she said he was looking more like him everyday?
What if she was talking about Toya/Dabi?
We know from flash backs at one point in time Toya/Dabi has red and white hair due to how his hair is changing from red to white.
And from what little I have seen Toya/Dabi does seem to toss fire at baby Shoto while in Rei’s arms
And that is the start of her breaking point. Her oldest son tried to kill her youngest son. There is clearly something wrong with him, how could she as a mother have missed that? She is asking herself all these questions.
Than the unthink able happens he son dies; kills himself while training when we told him he wasn’t to be training not by himself anymore it wasn’t safe for him.
Then her youngest it growing up and looking more and more like the son she has lost