Also, even if Asley decided to accept the forced arrangements for the sake of Rina, at least he could put out some terms and conditions, it's not like he's in a position where he's not valued and unique to make negotiations. Given his knowledge and talents (even strong enough to defeat rank A monsters as mentioned), he's so valued by Irene that he could actually make some demands and they'd agree to that, the blackmail was a tactic to pressure him, albeit a bad decision.