Blockade

Defense (lvl. 30) Blockade

Mana Cost: 80
Cast Time: Instant
Range: Self
Cooldown: 60 sec.

Increases chance to block by 25% and decreases movement speed by 10%. Any damage you take increase attack speed by 6% and can be stacked up to 5 times.
You can't be Knocked Down or Pushed while the spell is active.

Combo
Gain Magic Shield while under Liberation.

Blockade is a background ability of any tank. It’s difficult to imagine a tank without this spell. Blockade gains extra chance to block attack and gains extra attack speed.

Don’t forget that attack speed also affects your global cooldown. So it’s great to have extra attack speed especially if you have many spamable abilities.

Immunity to knockdown will help you a lot in PvP.

Blockade also has a very nice combo that gains you magic shield.