Looking for bl title, the mc got rebirth as a crown prince and he has a stepbrother is an ...

Looking for bl title, the mc got rebirth as a crown prince and he has a stepbrother is an illegitimate son, blonde and blue eyes. The step brother was the actual biological son of the emperor. The MC is not but because her brother is powerful a d control, it haven't reveal yet. Forgot what chapter I last read. But the Mc is helping the stepbrother to avoid being killed like the original story.