Arelith

Using the link at the end of this post as a guide, give Blackguards spell-casting as equivalent to Paladins. Since both Paladins and Blackguards are strapped for stats, it probably wouldn’t hurt to give Blackguards a bonus to their Wisdom stat at specific levels (maybe +1 WIS/5 levels) to help with reaching the required amount of Wisdom needed to cast all of their spells.

With regard to Corrupting Weapon, I’d suggest converting the effect of the Inflict Serious Wounds spell as its current iteration into a new spell entitled Corrupting Weapon. Then as a 4th level spell, creating a new spell called Desecrating Weapon that has the same effects as the current Inflict Critical Wounds.

https://www.d20srd.org/srd/prestigeClas ... kguard.htm

We plan to add spells to blackguard and assassin eventually when we get the scroll issue for new classes fixed. I'm putting this in denied just for the sake of not cluttering the approved suggestion box, as we don't have a good timeline on when it'll happen.