It is quite a long story please read and advise.It is a case of a very toxic marriage between my late aunt and her late husband,the marriage was never approved by my late aunt's mother in-law and both she and her husband were of different religion(my aunt been a christian while her husband a muslim).They eventually went ahead with the marriage anyways and that was the beginning of her miserable life with her husband,the husband wanted to convert her to islam which she strongly object to till her untimely death.The husband who is very learned (A renowned professor) and well to do man was kind of a puppet to his mom and they both made her life miserable in ways you won't ever imagine. My aunt never had any of her four kids(all grown up now) in her husband's house as the man will chase her out each time she's due for delivery and will only allow her back after the intervention of his colleagues,the king other notable personalities. This was the condition that surrounded her during her child bearing years,needles to talk about the trauma she always go through during pregnancies and how her husband will always blame her for allowing herself to get pregnant.He does not eat her meals neither do they ever discuss about anything, they were like sworn enemies living together as husband and wife.He was only responsible for her children's school fees while she took care of every other thing you could think of concerning her and her children,you will never believe she's the wife of this man on seeing her and the kids never had any atom of good memories with their dad. Her husband had a son from another woman his mom married for him.My aunt continued staying married to this man despite all the advises given to her,she was strongly against divorce as a very strong Christian that she is(An S.U).That was how she lived her miserable life until her husband unfortunately died over a brief illness, after the burial her mother in-law called to ask her what she's still doing on earth and that won't she join her late husband, she also told her to get ready to join her husband soon and exactly two months after her husband's death, my aunt mysteriously fell and died on the Altar while praying in her church,exactly two moths after my aunt's mother in-law died too. The three of them(my aunt,her husband, her mother in-law) are all late.Things started unfolding after their deaths,this man was very rich and has properties everywhere of which my aunt and her children has no knowledge of,it didn't end there my aunt's husband used an elderly man whom he's not related to in any way as his next of kin.Now this strange man he used as his next of kin has refused to release this man's money and properties to his children, though my aunt's kids have refused to have anything to do with their father's wealth stating that their mom gave them everything they ever needed in life.Now remember I told you about a son he had with another woman, the said son is now fully back to reclaim all their father's wealth and possessions from this man but he has refused to let go of any,he has been dragged to the king,different group of organizations but all efforts to reclaim his father's wealth and possessions from this man proved abortive. This man(my late aunt's step son) came to meet my mom to help him talk to my aunt's children to get involved so they could claim back their dad's wealth and possessions from this man but they have strongly refused to be involved. Please what do you advise? What steps should he take to reclaim their dad's wealth and possessions from this man, remember he was unfortunately used as the next of kin.Thanks.