Cap'n Kobold
Hero
Undying patron as in Undying Light? Or The Undying from . . . SCAG? Is that basically undead-based powers, or just making the Warlock really hard to kill?
What race is the character?
What was the specific evil that he has sworn his Oath of Vengeance against?
Now, "Lost or forgotten Goddess" that he is married to sparks a number of ideas. (None of which are actual goddesses of course, but the character doesn't have to know that.) Was the marriage made in person? Is that what gives him his powers? Why did the paladin turn against his wife after they were married?
The best way of fitting this into Eberron I think would be a Paladin of the Blood of Vol. The idea of an Undying Warlock is pretty much Blood of Vol all over. The Paladin could be a follower of that religion, on their way to becoming one of the undead martyrs. His Patron is Vol, who he has/will turn against when he discovered that she was using the religion as a front for her own machinations.
That covers the Lost/Forgotten Goddess quite nicely. Those who choose to become undead martyrs could be known as the "Consorts of Vol" and by symbolically married as part of their ceremony, allowing Vol to influence them and slowly turn them into undead. (Covering the married bit.) A true follower of the religion would be horrified to discover the truth about Vol, (covering the rebellion against the patron bit) and might indeed swear a Blood Oath of Vengeance against her. Hence why Paladin.
What race is the character?
What was the specific evil that he has sworn his Oath of Vengeance against?
Now, "Lost or forgotten Goddess" that he is married to sparks a number of ideas. (None of which are actual goddesses of course, but the character doesn't have to know that.) Was the marriage made in person? Is that what gives him his powers? Why did the paladin turn against his wife after they were married?
The best way of fitting this into Eberron I think would be a Paladin of the Blood of Vol. The idea of an Undying Warlock is pretty much Blood of Vol all over. The Paladin could be a follower of that religion, on their way to becoming one of the undead martyrs. His Patron is Vol, who he has/will turn against when he discovered that she was using the religion as a front for her own machinations.
That covers the Lost/Forgotten Goddess quite nicely. Those who choose to become undead martyrs could be known as the "Consorts of Vol" and by symbolically married as part of their ceremony, allowing Vol to influence them and slowly turn them into undead. (Covering the married bit.) A true follower of the religion would be horrified to discover the truth about Vol, (covering the rebellion against the patron bit) and might indeed swear a Blood Oath of Vengeance against her. Hence why Paladin.