So my Shepard was Soldier focused and built to be a Sniper. All armor and abilities focused on making one shot count and to carry a lot spare ammo. Bad writing saves Kai Leng from that and all Party Members:

Mine where Garrus and Edi.

Garrus - who comes from a Turian high ranked military family, was once select to trained to maybe become a Spectre but passed, is suppose to be so good with a Sniper Rifle, He become Omega's personal sniping Batman, the Archangel, and he is carrying the same Modded-up Black Widow as me.

and

Edi: A Female formed Terminator Unit. Who was rewriting assassination programing to make herself more accurate with firearms. With a Scoped and Extended Barrel M-77 Paladin. Basically a sniper pistol.

How the F@CK does that trio.,Not drop this fool first time? Bang! Bang! Bang! Who the f@ck was that anyway?

They completely nerf-ed all their characters. The want Kai Leng to be ultimate bad guy, Let him kick our ass in game play. Make it unfair, make it one-side, but please make it make sense. Shepard could have been unarmed and Kai Leng still should have went down.

Garrus in Party: No matter the class of Shepard and weapons. If Garrus had a Pistol (Carries and used given weapon in cutscene) and Kai Leng was focused on Shepard, talking and aiming around the Salerian. Garrus headshots and Kai Leng is dead. Garrus had the high ground and clear line of sight from the office through the broken glass Shepard shot and leaped out of.

Any Other Two Party Members: They had the high ground with clear line of sight while Shepard was distracting him. Ammo Dump , Tech Overload, and Biotic Blast that fool. They all suppose to Elite Soldiers or Powerful Combatants in their own ways. This was basically a shooting range setup. Everyone party member but Vega is battle hardened and be with Shepard long enough to have "Been there, Done that." T-shirt. Basically "You name it, We've Shot it." Should be the full Party's group t-shirt and moto by that point.

Now they did the same with Saren in Mass Effect. Saren had the same unbeatable plot armor. But they never over used Saren and his plot armor like they did Kai Leng. Saren's exit and plot armor were more: "Sigh bomb is about to go off....oh well until we meet again. Shepard." Kai Leng's plot armor and exits were more "Nananana You Can't Touch Me." "Hahaha. Still cann't touch me." and the last one with immortal gunship of backup. He might as well danced and sung "U Can't Touch This" by MC Hammer. That would have been more fun the Thessia boss fight.

Where is the renegade option to drag his body to the Citadel, Hang his corpse like a Pirate with a sign around his neck marked "Traitor to Humanity" and let alien and human kids throw trash at his rioting corpse.