YEA OKAY SO I DON'T KNOW HOW TO USE THE SPOILER TAG HERE SO IM JUST GONNA DO IT MANUALLY LOL PLEASE DO NOT READ AHEAD IF YOU DON'T WANT TO BE SPOILED
okay so, the archduke will pretend as if he fell for Sovieshu LOL in order to protect Navier and he will fall for Navier but will take the antiode but ALAS, it will have no effect since he is actually already into Navier with or without the potion and did I mention that he was actually the one who gave the potion to Navier in the first place? hahaha he knew the effects and yet he drank the potion right in front of her. Basically he's just a tsundere lol and the potion gave him an excuse to express his emotions to her and before the divorce, he will ask Navier to run away with him to Rypt/ Rift (his home country) but Navier will reject him (poor Kafmen) even after her divorce, Kafmen still loved Navier even when she's already married to best boii Heinley.