Mace Windu...

Mace windu has terrible damage even with defence up, terrible defence, terribly useless skills and is very slow. His only value is his hp which is still average at best for a tank. I would literally take any other tank/support over him.

In making mace windu the developers literally took a giant dump and named it after the most powerful warrior currently in the game.

In short: don't use him, Ever.