After almost 2 years of playing MKDA, I've come to the conclusion that Jax is the best defensive player. The only other character that comes close is Hsu Hao.

Jax's Judo style and Hsu Hao's Wrestling style are the best styles' to use. With the aid of the Reversal move and good timing, these 2 are unstopable. One of my favorite moves to use with Jax is doing a reversal when the opponent punches, and press 1 on the controller for the piledriver. It's the best!