The contract said someone in the Duke family + he has a huge ego. That's all really I can say
So yeah, originally that contract wouldn't have any power over MC or OGMayvie unless it was signed.
In the original novel which MC's friend read, the family of OGMayvie business bankrupt, so OGMayvie have no choice but to fulfil the contract with whitehead to pay debt.
In this life where MC possessed Mayvie body, she managed to save her family business and made it the wealthiest.
That's why in this life, she and her family ignored whitehead always coming to demand them to fulfil the contract.
But since whitehead is very violent and have power, plus very sly.
MC worried she might one day got forced to marry him either by power or by pressure from other nobles/royals.
So MC decided better get herself the guy with the most power who is the only person the whitehead scared of.
Cant wrap my head around his way of thinking, why is he even offering the marriage contract when he isn't even a direct descendant of the people who made the initial contract. He says it himself, he's adopted. Does that even count as a descendant? Or maybe he's someones cousin in the family, then that would make sense...