I know that typically an Oathbreaker has turned from the "good"
Doesn't necessarily follow. You could break an Oath of Vengeance by being merciful for example.
Oh yes, I agree that Oathbreaker could totally apply to other situations, though I'm not sure the necromantic, etc class abilities would be a natural fit for someone who had been too nice to be a vengeance paladin
. I was just referring to the official D&D definition as "An oathbreaker is a paladin who breaks their sacred oaths to pursue some dark ambition or serve an evil power. Whatever light burned in the paladin's heart been extinguished. Only darkness remains." For Minthara, it's probably not the case that she had light burning in her heart before she turned to the Absolute, but I reckon the subclass could still work for her and help give grounding to her story as someone who has turned from Lolth to a new god.
EDIT: Btw, and with apologies to those who have already seen me banging on about this in another recent thread, I think there is an important distinction between breaking one's oath (and getting the Oath Broken condition and losing the ability to channel one's oath) and actually embracing the Oathbreaker subclass which requires a further commitment to the Oathbreaker knight in BG3. I reckon the Oathbreaker subclass would suit Minthara given her story. But if I were roleplaying a Vengeance paladin who had let go of their anger and learned forgiveness and mercy, I'd probably just stick with the oath broken condition and then stop levelling as a paladin and instead multiclass into something I felt better represented their new direction such as bard, cleric, fighter, etc.
