Tristan Thompson is taking another legal step to secure long-term care for his younger brother, filing for conservatorship over 19-year-old Amari Thompson. According to court documents obtained by Page Six , the NBA veteran is seeking to become Amari’s limited conservator, citing his brother’s inability to manage basic personal needs and finances due to a developmental disability. The filing outlines the extent of Amari’s condition, stating he is “unable to properly provide for his personal needs for physical health, food, clothing or shelter,” and cannot manage financial decisions or protect himself from “fraud or undue influence.” The documents also note that Amari is not in a position to weigh in on the conservatorship due to his intellectual disability and developmental delays. Amari lives with Lennox-Gastaut syndrome, a severe form of epilepsy that can cause frequent seizures and long-term cognitive impairment.…