Freeing the spawn doesn't break the Oath of Vengeance either, FYI.
Well. That is totally correct too. Those spawns, as evil as the may be or not didn't do anything againts a oath of vengance.
Many times, paladin role is mistaken. People think of them a judge that interpret the law, they aren't. Oath strictly works by the letter of the law. There isn't any room for interpretation. Oath is a moral code in function totally amoral in execution.
Yeah, as I said. I can get the 'they're undead and must be destroyed according to your oath" idea... except the only reason the quest is happening is the vampire I've been travelling with, and not destroying. Which has never caused the slightest problem with my oath.
So I guess we've got a classic paradox of the heap going. Letting one vampire live after showing they're more than a mindless monster and can control their hunger is okay, while 7000 is an oath violation. So would 2 be okay? 6999? What number of vampires requires me to destroy them, vs it being okay to be friends?
One thing have nothing to do with the other. As I said oath have no room for interpretation. Let live any number of undead should break the oath.
The posibility of just travel (not to mention romance XD) with Astarion without breaking your oath is a game error. The solution of an error is fix that error, not change the things that are correct.
If, for example, the flame arrow is bugged and does 3d6 fire damage, you don't fix it by making all the elemental arrows do 3d6 damage