Yazdin

For the Church in the East, Yazdin was the main philanthropist in late-Sasanian times. Guidi's Khuzestan Chronicle notes these:

18 Now at that time Yazdin from Karka in Beth Garmai was well known at the king’s place of residence. This man was the advocate of the church, like Constantine and Theodosius, and he built churches and monasteries all over the place, modelled on the heavenly Jerusalem. He was is great favour with Khosro, just like Joseph in Pharoah’s eyes, and even more so, with the result that he was famous in both the Persian and the Byzantine kingdom. It is said that Yazdin every day, from one morning to the next, sent the king 1000 staters.

27 Then a number of troops rebelled against Khosro, and Shamta, Yazdin's son, and Nihormizd rose up and made Khosro's son, Sheroi, king....

28. Then Nihormzid and Shamta requested the king Sheroi, Khosro's son, that they might kill Khosro, and on his giving them permission they went into the place where he was confined, and Shamta raised his sword to strike him. Khosro wept in front of him and said, "What wrong have I done to you that you should kill me?" So Shamta did not strike; but Nihormizd hit him on the shoulder with an axe, repeating the blow on the other shoulder. Sheroi his son mourned over him and he was buried in the tomb of the kings. Shamta did this because Khosro had plundered the house of Yazdin his father when he died, and had brought many afflictions on Yazdin's wife, while Nihormzid acted thus because [Khosro] had killed his father. Khosro son of Hormizd reigned thirty eight year.

Siʿrt #81 (my translation):

Yazdin the generous and virtuous, whose fame spread everywhere, at the same time as the generosity: he built churches and convents in the East. Kosrau conferred upon him great authority and entrusted him with the administration of all the provinces from Bet-Garmay to the lands of the Greeks: it was he who lent his support to the faithful in the affair of the excommunicated Gabriel after the death of Gregory the Catholicos.

John of Kashkar: he succeeded Yazdin after his death in the administration of the provinces. He has a convent in the region of Kashkar. After Khusro's death he fell into misery; his property having been confiscated. ...

Then Siʿrt #92:

During this time, that is to say, after Heraclius, emperor of the Greeks, had returned from Persian territory, as we have said, Kosrau, seized with fear and terror, did not leave Seleucia. After the death of Yazdin the Faithful, he had pursued Samta, his son, and confiscated all his property; he even imprisoned his mother and took away everything she owned.

Thomas of Marga 1.35 has similar but, you know... Thomas.

That Gabriel would be Gabriel of Sinjar. From these we must gather that Yazdin predeceased Khusro II and was active circa AG 920-35 (AD 610-25) - I'd suspect a narrative buildup in the common source (Kodeh-Nameh?) except that Ishoʿyahb of Nineveh seems aware of it, so, we can allow it for 939 = 628. Sheroë, I glean further, figured John as the main (surviving) beneficiary of Khusro's piracy, so did unto John as Khusro had done unto Yazdin.