Thanks. I keep looking for the chapter where he said something (the advice) and I give up. Fortunately someone commented here.
So all along the marquise have known that Heimdall is Joshua's father. I suspected the marquise to be Heimdall but seeing Duke Agnus really caught me off.
Did the duke really die in the first life? Because I remember that the emperor went missing last time as well. If he survived the same way in this life, then why didn’t he help his son leave the 4th prince? Cause he knew the imperial family can’t be trusted. Unless the duke got killed off later on by the 4th prince
I knew the Duke's supposed death was too suspicious since wr didn't see a body. Also, Joshua is most likely aware of his father's current status since he addressed the creepy mustache guy and told him that he has taken his advice to heart (this guy told Joshua that his father is the most dangerous existence above the emperor himself). I'm so looking forward to what unfolds next