Also He loved her 2.0
Spoiler!
Herdine has always loved Blair, but because of his black magic cursed mana, he had to get away from Blair. the curse shorten Blair’s lifespan. the closer he stayed with Blair, the shorter her lifespan is. so he went on a voyage trying to find a way on how to break the cursed.
he thought the bi*** saintess can break the cursed but she was delulu in love with Herdine. the saintess manipulated him by saying if his wife Blair hates him then the cursed can be broken (which is partly true) yes Herdine and Blair’s love for each other strengthen the cursed but what they didn’t know was, both parties have to hate each other in order to break the cursed but they thought only one partner’s hate can break the cursed. that’s why Herdine went along with the saintess’ bullshit by hugging her in order to make Blair hate him (but until the end Blair and Herdine loved each other) after seeing Blair’s broken face after he hugged the saintess, he decided to just live with the cursed. he couldn’t stand seeing Blair’s broken face. he sent the saintess away and wanted to start a new happy life with Blair and their son but few days after sending the saintess away, Blair was murdered.
I like to post spoilers for the stories I find interesting because I don't have much time to read novel due to busy schedule
you will find me in most romantic historical manhwa comment sections 
you will find me in most romantic historical manhwa comment sections