The main villain of Mass Effect 2, now in Lego form. Obvious spoilers are obvious.
About this creation
Harbinger is widely regarded as a weaker character than Sovereign. This is understandable.
However, around the time of the Arrival DLC, things start to get interesting. It admits that Shepard is a threat. Heck, it might even be scared.
Think of things from its perspective. You're going about doing what you've done for billions of years with little trouble, when suddenly, some weakling organic actually kills one of your number. So you kill them in return. But then, two years later, they reappear somehow, stronger than ever, in an even bigger ship than they had before. Using parts stolen from the bodies of your dead, they storm your base and take out all of your most powerful defenses. Then they kill an innocent child, before blowing said base up. And it doesn't even end there; they then proceed to sacrifice thousands of their fellow organics just to inconvenience you. Yeah, I think Harbinger is a bit unnerved by Shepard.
I read a crazy theory somewhere on the internet suggesting that the reason Harbinger acted against Shepard with so much fury in the opening of ME2 is that it and Sovereign were either romantically involved or best friends.
While it is strange to imagine genocidal spaceships as forming attachments like this, one must admit that this makes the above description about ninety times worse. All in all, I don't think Harbinger was a terrible character, even if its taunts got annoying after awhile.
"We are assuming control."
I may eventually build a Reaper Destroyer, incidentally, but if so, it probably won't be for a long time.