I went with a balanced character who has ranged and melee skills + the summon ghost skill. The tower was hard for me, but I used a mix of ranged tactics that helped me get by. You might try luring out one or two skeletons at a time if you can. Also, have you purchased better equipment?
IMO some kind of ranged attack is a must for many portions of this game so far (and I just finished the Tower you speak of).
