There persists a Problem.

Time and time again, organics create beings so advanced that they overpower their creators. In mankind's Cycle, this issue has been duplicated ad nauseum. The Quarians created the intelligent Geth, whose conflict with them caused the Morning Wars. The Salarians prematurely uplifted the warmongering Krogan, which led to the Krogan Rebellions. Even the Reapers themselves were a creation of the Leviathan, eventually overpowering their masters and decimating the Leviathan population. These wars are the Problem that plagues the Milky Way Galaxy, but for every Problem, there exists multiple solutions.

Destroy, Control, Synthesis. These three words define every ending a Mass Effect player has ever experienced. But while this choice may be the last in the trilogy, it is not the first time Shepard has made this decision. In fact, the themes of Destroy, Control, and Synthesis are explored in all three major Mass Effect 2 DLC missions, namely the Arrival, Shadow Broker, and Overlord DLC respectively. Mass Effect 2's DLCs represent each of Mass Effect 3's endings, with each DLC conveying how resolving the Problem of the Reapers is more morally dubious than it may seem.

Here are each of those major DLC missions and the endings that they explore:

Destroy: The Arrival

In the Arrival DLC, Shepard's killing of 300.000 Batarians in order to delay the Reapers is reminiscent of Shepard sacrificing the life of synthetics to defeat the Reapers. After being rescued by Shepard, Alliance Scientist Kenson reveals that in two days, the Reapers are using the Alpha Relay to invade the Milky Way. Her solution to their arrival: hurl a massive asteroid at the Relay to destroy it and delay the Reapers. The destruction of the Relay, however, would kill 300,000 innocent Batarians who reside on the asteroid. This moral quandary is an example of the Trolley Problem: is it morally responsible to kill thousands of Batarians if doing nothing would most certainly kill countless more lives throughout the Milky Way? Shepard's answer is yes; deciding to destroy the Relay and sacrifice thousands of Batarian lives, Shepard successfully delays the Reapers for another six months.

Shepard's decision isn't without consequence, however. The Council puts Shepard on house arrest leading into the events of Mass Effect 3. Still, Admiral Hackett stands by the Commander's decision, saying that Shepard "did what you did for the best of reasons."

This sacrifice of Batarian lives is reprised should Shepard choose the Destroy ending in Mass Effect 3. By destroying the Reapers, Shepard also chose to destroy all synthetic life, including Geth like Legion or AI like EDE. In spite of their deaths, Hackett once more backs Shepard up, conceding that "It will take time, but we can rebuild everything that was destroyed."

Shepard recognizes the tremendous sacrifice needed to stop the Reapers, professing this final speech at the end of the Arrival DLC:

"Maybe we'll lose half the galaxy. Maybe more. But I will do whatever it takes to rid the galaxy of the Reaper threat. However insignificant we may be, we will fight, we will sacrifice, and we will find a way."

In the DLC, that "way" Shepard finds is killing 300,000 Batarians. In Mass Effect 3, that "way" is the death of countless Synthetic lives.

For both the DLC and in the Destroy ending, Shepard decides that the needs of the many outweigh the few, doing whatever it would take to stop the Reapers.

Control: Lair of the Shadow Broker

In the Broker DLC, Liara's usurping of the Shadow Broker only to become the Shadow Broker herself is reminiscent of how Shepard takes control of the Reapers at the Crucible.

Shepard's defeat of The Shadow Broker left a massive power vacuum in the Broker's wake. But rather than destroy the Broker's network and his many valuable contracts, Liara decides to assume the role of the Broker herself. She orders the Broker's agents to continue business as usual, and orders them to provide Liara (and by extension Shepard) with valuable information. By controlling the Broker's information network, Liara receives vital intel during the Reaper War, including information that led Shepard into activating the Crucible, a mega-weapon that defeats the Reapers.

Originally, Shepard may question Liara's decision. Even Liara concedes that the power she has is inherently dangerous, stating that "In just 10 minutes, I could start a war." Despite this, Liara reiterates the power of this information, replying that "It was either that or lose everything: his contacts, his trading sources. Those will really help us." Liara contends that destroying power no one else has is a waste, acknowledging the unique utility of the Broker's network.

Just as Liara seized control of the Broker's agents, Shepard seized control of the Reapers in the Control Ending.

Liara's belief that power from a malevolent source can still be utilized for good is a principle shared by Shepard should he choose the control ending in Mass Effect 3. In that scenario, Shepard sacrifices his organic form to become the ruler of the Reapers, becoming a god-like entity that controls all Reapers in the galaxy. He makes the same decision Liara did by assuming control of the Reapers and acting as an unopposed god who has power no one else in the galaxy has. Shepard recognizes the value in the Reapers in the same way Liara valued the Broker's agents, saying this:

"There is power in control. There is wisdom in harnessing the strengths of your enemy."

This "power" allows Shepard to control the Reapers into helping the galaxy rebuild after the Reaper war.

By controlling the Broker's intel in lieu of destroying it, Liara's decision asserts that absolute power doesn't corrupt absolutely, and when in the right hands, can do more good than harm.

Synthesis: Project Overlord

In the Overload DLC, the fusion of David Archer and Geth technology mirrors the Calalyst's fusion of organic and synthetic matter in the Synthesis ending.

The objective of the DLC's eponymous Overload project is to fuse David Archer's mind with a VI interface. In doing so, this will allow Geth and mankind to communicate and understand each other in ways previously not possible. While Galvin Archer initially claims that it was David who volunteered to be fused with the Geth, David's outbursts to "MAKE IT STOP" make it abundantly clear he is forced into these experiments. Galvin later concedes that "The Illusive Man doesn't broker failure," attempting to justify his unethical experiments on his brother.

Galvin rationalizes his work into a mere equation. When pressed by Shepard about his experiments, he responds with this:

"If my works spares a million mothers mourning the loss of a millions sons, my conscience will rest easy."

Galvin contends that it is ethical to sacrifice the life of a single person if it will save a million more. This may sounds similar to the Trolley Problem, but there is a key distinction.

The Trolley Problem is a dilemma in which death is unavoidable- it is certain the train will run over somebody. The only decision, therefore, is whether it is ethical to minimize suffering by running over one person instead of five. In the Arrival DLC, it is a certainty that the Reapers are coming, and while thousands will die by hurling a meteor at the relay, there will be less suffering than if the Reapers were to invade and kill countless more.

The Overlord project lacks this certainty. Even without hindsight, there is no guarantee that Galvin's experiments will save lives. In addition, there are experiments that, while they may take more time or are less likely to yield immediate results, are undertaken with the consent of its test subjects. And with hindsight, it is clear that Galvin's words bear no fruit. In Mass Effect 3, if Shepard allows Galvin experiments to continue, David was able will be able to communicate with the Geth more and more. However, he'll eventually relapse into a vegetative state, prompting Galvin to euthanize his brother out of mercy. Galvin experiments demonstrate that a supposedly "necessary evil " is still evil, and that his experiments on his brother are far from justified.

Overload DLC also mirrors Synthesis in how it infringes on the rights of the people that Synthesis aims to protect. Just like David did not consent to being experimented on, the people of the Milky Way Galaxy did not consent to becoming organic-synthetic hybrids. Although not much conveyed in-game, it can be inferred that there are many anti-synthetic organics who would be opposed to altering their DNA to become synthetic hybrids. While others may argue that this infraction of aliens' right is for the 'greater good' of the galaxy, this is yet again the same justification Galvin used for his experiments on his brother. The only difference is that this is on an immensely larger scale, affecting not just one test subject, but trillions. Even if Synthesis comes with the promise of peace, the Synthesis ending is achieved by a single person deciding the fate of billions in the Milky Way Galaxy. It is unethical for Shepard to make that decision for them.

While Project Overload is a failure, the project's vision can be realized in the Synthetic ending. Just like David was used as a conduit in Project Overload, Shepard sacrificed his body so that his organic matter could fuse with synthetic matter. Essentially, the Synthesis ending is what Dr.Archer hoped Project Overload would accomplish. The two major differences is firstly, that it is Shepard himself who decided to sacrifice his life for the Synthesis ending; and secondly, that the sacrifice of Shepard's body immediately produced results. After Shepard throws his body, an explosion emanates from the Crucible that reaches across the galaxy, almost instantaneously combining organic and synthetic matter. This fusion is what allows for the coexistence of synthetics and organics, altogether ending the conflict between the two ad infintium. Even the Star Child touts Synthesis as "the ideal solution," stating that Shepard's Cycle is the first to truly be ready to integrate with synthetics. These are the ideal results that Galvin Archer sought to grasp, but failed to ever reach.

In spite of his efforts, Galvin Archer's unethical experimentations on his brother demonstrate that the road to hell is paved with good intentions, and that synthesis between organics and synthetics is easily said than done.

Conclusion

Ultimately, there is no single, perfect solution to the Problem. in the Destroy Ending, it is unethical to commit the genocide of synthetics; it in the Control ending, is unethical to yield power to an unopposed, omnipotent ruler; and in the Synthesis ending, it is unethical to forcefully change the DNA of organics. Mass Effect 2's DLC are only a dip in the water when it comes to exploring the solutions and their many ramifications. Yet they are still the starting point when it comes to truly understanding the ending of Mass Effect 3.

For a series as great as Mass Effect, there is no truly 'good' ending. There is no war without casualties, no success without sacrifice. For every something gained, something is lost too, whether it be a loss of humanity, a loss of one's rights as a human being, or, perhaps most gravely, the loss of human life itself. Shepard's final decision in Mass Effect 3 shows the tremendous moral dilemmas that are repeatedly explored and executed throughout the trilogy.