Ill just say it bluntly, is witchcraft any good?
Unless you've discarded it as too powerful (a valid opinion), I think Blind alone makes Witchcraft worth having. Oath of Desecration is of course powerful; I'd suggest Witchcraft does quite well with summons as well, both creating and killing them.
This game isn't hard if you're pretty comfortable with tactical TBS games, so if you're good, I suspect almost any character build will get you through the game. But I wouldn't call Witchcraft the weakest skill choice in the game.
