I did Kensai BlackBlade and definitely effective on the battle field. Just one warning, no mage armor kind of sucks. Find a way to get it, I paid the party wizard to write scrolls to use on me. That worked well till I could get bracers of armor. Having the black blade and not being to wear armor left me with a lot gold to spend as I had no need enhance weapons or armor. Over all fairly solid class, grab toughness at 1st level you'll need the hit points.