Shadow Broker (enemy)

The Shadow Broker is an individual at the head of an expansive organization which trades in information, always selling to the highest bidder.

Mass Effect 2
After tracking down and infiltrating the Shadow Broker's ship, Shepard and Liara break into the Broker's intel center and confront him in person. The Shadow Broker is revealed to be a member of a pre-spaceflight race called the yahg. Liara surmises that because the yahg were not discovered until 2125 CE and the Broker's ship is considerably older than that, this yahg usurped the original Shadow Broker years ago and has been running the organization ever since.

Capabilities
Offensive:
 * He will continuously fire his Revenant while trying to close the distance on you.
 * Once he is close enough, or after a while, he will charge at you. This charge attack can break the pylons you can use to take cover, and damage you through it.
 * He can melee you with his shield if you stay close for too long.

Defensive:
 * In stage one, he will have shields, armor and health. He will replenish shields and armor once these defenses have been stripped.
 * In stage two and three, he will have the same, but also carry an impenetrable omni-shield.
 * During the time his shielding and armor are stripped, he will be invincible to anything but a melee attack.

Tactics
General Tactics:
 * During stage one, use rapid-fire weapons with Disruptor Ammo and Overload on his shield, followed by slow-firing weapons with Incendiary Ammo and Incinerate or Warp on his armor.
 * During the second and third stages, use the same attack method. However, techs and biotics now need to be aimed carefully, since they will have to bypass the shield he is carrying. When you aim at him, aim at his left side leg or arm. If you shoot him enough, he will stagger, which is a good time to unleash powers on him. You could also try to run behind him using the Infiltrator's cloak or the Soldier's Adrenaline Rush ability. This, combined with a charged shot from a Geth Plasma Shotgun will take him down quickly.
 * Once his shields and armor are taken down, run up to him quickly, and melee him. Repeat the stripping/melee process three times to finish him off.
 * It is useful to note that using either Liara's Singularity or Stasis will stun the Shadow Broker for a brief time, giving you the chance to inflict more damage. The effectiveness is increased if you trained Liara's mastery to "Asari Controller" since it reduces power recharge time.
 * The Arc Projector is very effective against the Shadow Broker. It penetrates his shield, deals damage and causes him to temporarily lower his defenses. This allows for better positioning and follow up shots with other weapons. Repeating this pattern can make short work of him even on Insanity difficulty.
 * You can continuously climb the two staircases in the back of the room, climbing up one, moving towards the other, climbing down then moving back to the first to keep cover between you and him, allowing you to use powers to wither his defense. The upside of doing this is as you both circle the obstacle, he will more or less ignore Liara. Any attempt to charge at her will generally result in him charging into obstacles and getting caught there, making this battle ridiculously easy.
 * The M-98 Widow sniper rifle is also a good choice, provided you are accurate enough to hit him behind his shield. Adrenaline Rush can help with this if you are not that accurate. If done correctly, using this tactic means you won't have to move at all throughout the fight except for the melee sequences.
 * Flashbang Grenades will make the Broker stagger and allow you to pepper him with gunfire for a few seconds.
 * If you really want any easy playthrough, then you need only confuse him so that he just stands there doing nothing. To accomplish this, head right until you're behind the pillar. If you stand close enough to the pillar to go into cover, the Broker will charge, and eventually destroy the pillar. If, on the other hand, you stand back from the pillar, enough so that the pillar is directly between you and him, the Broker will instead, just stand there.  At this point, move slightly to the right, enough so that you can see him and even shoot at him, but he will not shoot back. At this point, you can just wear him down.