Sword of Night and Flame is so busted and stylish, but also endlessly stat hungry. You can switch between optimizing for the Int and Faith skill by finally spending all your Larval Tears. Also only use the main weapon for trash mobs, for Boss fights it's really all in the Skill.

I'm unsure if it is ever truly outclassed in the Straight Sword Class. Spamming Square Off or Power-stanced attacks, is a whole other play style. But you can stack so many boost, especially in the end-game, on top of the two Skills for the ^Sword^ ^of^ ^Night^ ^and^ ^Flame^, that you one or two shot so much stuff.