
I love the main couple also Ian and the other prince too, but still, i can't trust completely in the witch ╮( ̄▽ ̄)╭

Iain and the prince's story reminds me a bit of this series by NAKAMURA Asumiko,
First part (Chapter 2)
http://www.mangago.zone/read-manga/tales_of_the_kingdom/
Second part
http://www.mangago.zone/read-manga/the_king_and_the_attendant/
I watched the raws and they end up together so i hope Natsuka change for the good and really fell for Seno because rn i don't like him #-.-)