I was reading fanfiction.net's rules and it seems that they only want stories there, so I thought I'd put my background info here :)
Zyntas Bloodwater is the Lord of Stormport in the Rainwood of the Stormlands. He is the youngest of the seven children born to Lord Rolfe and Lady Meya of House Coldwater of Coldwater Rush in the Vale.  He, along with his elder brother Bryan (sixth child) were sent off to be fostered when Zyntas was four years old. While his brother was sent to be fostered in the North, Zyntas was sent to the Riverlands to be fostered by Lord Dawsin Wayn. The connection between House Wayn and House Coldwater was due to Lord Wayn's wife, Lady Alara Moore of House Moore in the Vale.
Just before Robert's Rebellion, Zyntas married the youngest daughter of House Qorgyle of Dorne, one Lady Aiana Qorgyle. They were granted permission to continue living in the holdfast of Lord Wayn, as he only had one other son, Lord Baryard Wayn. When Robert's Rebellion broke out and Hoster Tully called his banners, Zyntas joined the men supplied by Lord Wayn, leaving his pregnant wife at Wayn's Holdfast. He fought with the Tully soldiers at the Battle of the Bells, and after winning the battle ripped the heart out of one of the last royalists to fall and ate it.  The man's blood soaked the Coldwater sigil on his armor, earning him the name "Bloodwater", which he later took as his own.
Zyntas was later part of the Battle of the Trident. There he slew Ser Jonothor Darry of the Kingsguard by plunging his sword into the knight's throat. He was locked in combat with Ser Barristan Selmy when Robert Baratheon slew Prince Rhaegar.  Zyntas was granted leave to ride back to Wayn's Holdfast to be with his wife instead of join the march south to King's Landing. His daughter was born shortly before the Battle of the Trident. He was twenty years old.
Zyntas' father, Rolfe Coldwater, was one of the lords of the Vale who sided with the royalists. Rolfe was allowed to take the black instead of face execution. Zyntas' eldest brother then became the acting lord of Coldwater Rush.
Zyntas' wife had a son and another daughter during his time at Wayn's Holdfast. Zyntas then joined the Iron Throne's forces during the Greyjoy Rebellion, only one year after the birth of his last daughter. During the Siege of Pyke, Zyntas slew Lord Blacktyde inside the castle. He was there when Balon Greyjoy bent the knee to King Robert.  He was then knighted at the age of eight-and-twenty, alongside Jorah Mormont and Jacelyn Bywater.
Zyntas and his wife and children later moved to Sandstone in Dorne to stay with his wife's family after she had become ill shortly after his return from Pyke. While there, Petyr Baelish, whom Zyntas knew from his childhood visits to Riverrun with his foster family, offered him an opportunity to ingratiate himself further with Jon Arryn by hunting down a group of Targaryen loyalists. Zyntas himself led the search and soon found and crushed the loyalists. Upon his return home, his wife's family told him that Lady Aiana's condition had worsened. After staying with her all night, she passed away at sunrise.
Zyntas and his children then went to Coldwater Rush, where he finally got to speak again to his family, including his eldest brother Royce, the lord of Coldwater Rush. On a visit to King's Landing, Zyntas was asked by Jon Arryn to uproot a group of slavers in the Rainwood. Partnered with Ser Hugo Flint, Zyntas and his men put the slavers to the sword. Jon Arryn and King Robert granted Zyntas the keep for his service, and he sent for his children to join him from the Vale.
1) Rolfe defeated Lord Brus Roxton in a duel to win Lady Meya's hand.
2) Zyntas did this to grow himself a reputation as a fearsome warrior, and knew it wouldn't be harmful as Dothraki do the same with horse hearts in ceremonies. Despite what many of the men present at the Stoney Sept said, Zyntas in fact only took large a bite of the heart.
3) This was the only time Zyntas had ever felt he may die in battle. Even close to death, Ser Barristan was a fierce fighter and Zyntas was thankful that Robert chose that time to kill Rhaegar.
4) Zyntas has a certain hatred for the Ironborn, and felt Robert would do best to execute Balon and all the lords who joined him in the rebellion.
(Because the game is more based on the show than the book, I will be using the GoT timeline where every season = 1 year, and not the asoiaf timeline. Therefore, at the start of this fanfic (and start of the GoT series), Zyntas is 36, Jayne is 16, Jon is 13, and Ella is 10.)