Mental Torture by wife

My brother is frustrated by his wife.He ha been married since 2010 but after few days of marriage his wife started creating drama regarding day to day housecores.gradually it became very usual.like I will not do any house core as I m not your servant do whatever you can do.she even threatened to do suicide many times and if asked for divorse she said she will not give divorce and make him suffer as she will not let anybody happy if she is not happy.They have 2 kids younger one is 8 years old and elder one is 13 years old.she didn't wanted to live with parents so they let them live separate in lower floor of the house but still she stops my brother and kids to meet with parents or sisters as she don't want them to do so.she is working.my parents looks after the kids when they r back from school.my brother wants divorse from her.we have tried councelling her many times in these years but all in vein.She don't listen to anyone and misbehaved with her in laws.can u please guide what to do in such situation.