Please need your advice

Happy new year po sa inyong lahat! I'm joan I need your advice regarding my sister case.. Nakapag abroad po ang husband ng sister ko since 1990 po ata to saipan.. may communication po sila ng mga ilang months tapos hindi napo nagparamdam ung asawa nya as in inabandond po nya.. nung mag time po nun nasa poder po ng byenan nya sister ko at dalawa nilang anak.. wala rin pong nagawa mga byenan nya.. nalaman nalang po namin na nagkaron sya ng asawa dun at anak, hindi po nya pinadadalhan ng pera mga anak nya d2 sa pinas.. ng mga high school na mga bata dun plang pinadalhan as in P3k lng a month trough sa mga kapatid at magulang ng lalaki.. lumipas po ang ilang taon accepted napo ng sister ko mga pangyayari.. humihingi po ng annulment ang sister ko, sabi po nila nag file na ung lalaki kasi nakakauwi na sila sa pinas tong mga panahon na ito... malaman laman namin eh nag file po sila ng presumption of death.. or pinalitaw nila na patay na sister ko... at may nakuha po kaming mariage certificate nila sa NSO.. bkit po narehistro sa NSO natin ung marriage certificat nila sa saipan? Ano po pwede naming gawin? kasi pinagloloko na po nila sister ko? and yun nga po bakit po meron silang file sa NSO? . Thank you and more power!

nalaman nalang po namin na nagkaron sya ng asawa dun at anak”- Did he contract another marriage? If he did, that marriage is invalid and illegal as far as the Philippine laws are concerned.
The subsequent marriage which he was able to register with the NSO was obtained through fraud or deceit on his part and I presumed that he was able to do it by instituting a summary proceeding which declared that your sister was presumptively dead. Of course, he did it without your sister’s knowledge. This process is being resorted to by unscrupulous individuals who do not want to undergo the rigorous and strict process of annulment of marriage. That certificate is a material evidence if ever your sister wants to sue her husband for bigamy. A person who marries again in bad faith is criminally liable for that crime.There are also other remedies which your sister can use to get support from him.