I wanted to start by saying I beat vanilla FFVI many times over the years, spanning from when FFIII(US) was released. This is my first hack of the game, and I enjoyed it immensely, to the point that I wouldn't recommend the original over this version. I was quite satisfied by the time I beat Kefka.
To the topic at hand though, before I ventured into Kefka's tower, I charted each character on a whiteboard (picture attached). I highlighted their strengths as I built them, and this helped me to build an excellent set of three teams for the venture into Kefka, and eventually helped me to build the winning team on the Kefka fight. There are a lot of specialties to keep track of, so did anyone else do anything like this?