Very little is known about Zero, other than that he showed up on the scene in Pandora and began taking and completing assassination contracts with lethal efficiency. Zero is Borderlands 2's assassin, whether by trade or by necessity, and he's ruthlessly good at what he does.
Specializing in stealth and dealing incredible amounts of damage to targets, Zero is one you'll be glad to have on your side in Pandora. Sticking with Zero and progressing his skill trees in the right direction will see you able to really focus a lot of damage on your enemies. Players will get the most out of Zero when they realize and embrace that his purpose is to deal ridiculous amounts of damage while remaining out of the crosshairs himself.
Some of his abilities increase movement speed and his special power is designed to keep him invisible to enemies - literally.
The special power in question, of course, is Zero's action skill Deception. If you played the original Borderlands, you'll recognize Deception as being similar to Lillith's Phasewalker skill.
When Zero uses Deception, he projects a holgraphic decoy of himself. Enemies will train their attacks on the holographic decoy rather than Zero himself. Stupid enemies.
But, then again, Zero does become completely invisible while the decoy is deployed so perhaps they aren't to blame entirely for their stupidity. Incidentally, while Deception is active and you are invisible, the amount of damage your next attack does increases. The longer you are invisible, the more damage you will deal when you finally strike. The catch, however, is that the cooldown period is longer the further you allow yourself to remain invisible.
Generally speaking, however, Deception has a pretty short cooldown period so you should be using this heavily in battle. The holographic decoy can be useful in dispatching enemies, sure, but if you're low on health and need to book it out of there, simple activate Deception and run like hell in the opposite direction.
Keep reading for more on Zero!
Like all of the player characters in Borderlands 2, Zero's skill tree branches in three directions. His are Sniping, Cunning and Bloodshed.
Zero's sniping branch is perhaps the most focused in the entirety of Borderlands 2. While other branches are more broadly designed, Sniping is almost entirely dedicated to Zero's prowess with, you guessed it, sniper rifles. There are some other weapons that Zero will excel with, but with abilities like Kill Confirmed and One Shot One Kill, it's clear that Zero will be a masterful sniper.
His second branch, Cunning, is more towards augmenting the way that Zero fights on the battlefield. These skills include things like Ambush which increases damage dealt to enemies from behind and Innervate, which increases your gun damage, health regeneration and movement speed while Deception is active.
Finally, we have Bloodshed. This branch plays heavily on Zero's natural lethality, giving him boosts to melee damage all over the board as well. The last ability in Bloodshed increases the effectiveness of Deception twice over again, deploying a second hologram, re-activating stealth and increasing the overall duration of the skill. This can be done multiple times in succession and only requires a melee kill while in Deception to activate.
If you're planning on playing cooperatively with friends online, don't count Zero out. He can be a great asset on the battlefield, dealing massive damage with his sniper rifle while staying out of the thick of things. In this way, when you're friend is playing as another character in the heat of battle and gets taken down, Zero is there to move in and revive you.
When playing as Zero in co-op, however, you'll want to make sure that you aren't relying too heavily on kill skills that require large amount of kills as these will be spread out between you and your allies.
Zero is a force to be reckoned with and brings more than his fair share to the battle.