The writers certainly shook things up on Sleepy Hollow Season 2 Episode 17. What a shame it took them until the penultimate episode though; it all felt too little too late for my taste.
Katrina proved herself to be a powerful witch, but she had to go all dark side to reach her true potential. It just seems so random doesn't it?
Had time travel been introduced earlier, I think it would have made a phenomenal story arc. Now, it's just going to be rushed and resolved too quickly. Unless, of course, the finale is a cliffhanger, which would suck if the show doesn't return.