Should I Let Garrus Kill Sidonis?

When It Makes Sense

• Good fit: You are playing a Renegade, pragmatic, or crew-first Shepard. Sidonis betrayed Garrus’s squad on Omega, leading to their deaths, and if your Commander believes that kind of treachery is answered with lethal consequences, letting Garrus take the shot is narratively consistent. It signals that you trust Garrus to handle his past, strengthens your bond with him, and grants Renegade points that can help unlock higher-tier Renegade dialogue later in the game.
• Good fit: Your Shepard lacks the Paragon or Renegade points needed for the Charm or Intimidate options, or you simply do not want to risk a failed persuasion attempt. The rooftop confrontation is tense, and without enough reputation the dialogue choices that spare Sidonis can backfire, leaving Garrus angry and the mission unresolved. Allowing the kill is the most straightforward way to complete Garrus’s loyalty mission and keep him moving forward.

When You Should Avoid It

• Warning sign: You are committed to a Paragon, lawful, or redemption-focused run. Sidonis is unarmed, cornered, and appears remorseful; executing him is an extrajudicial killing rather than battlefield justice. If you want Shepard to be the kind of leader who shows mercy even to traitors, or if you are trying to maximize Paragon points, you should strongly consider intervening.
• Warning sign: You care about long-term character growth for Garrus or want to preserve every possible Mass Effect 3 callback. Letting the kill happen closes off the mercy branch and can define Garrus’s arc by vengeance rather than restraint. While the choice does not lock or break a romance with Garrus, it does shape the tone of his personal story across the trilogy.

Pros and Cons

Pros

• The choice validates Garrus’s trauma and gives him tangible closure. He has carried guilt over his squad’s deaths since Omega, and allowing him to confront the person responsible can feel like a natural, if grim, resolution of that storyline.
• It avoids the mechanical uncertainty of persuasion checks. If your Paragon or Renegade score is low, or if you are unsure whether the right dialogue option is unlocked, letting Garrus shoot is a reliable path to finishing the loyalty mission without souring the moment.

Cons

• It pushes Shepard toward Renegade morality and away from a pure Paragon path. That may lock out certain Charm dialogue options later or move your character in a direction you did not intend.
• It ends Sidonis’s story with death rather than remorse or redemption. For players who enjoy seeing characters face consequences through exile, confession, or personal change, killing him removes that narrative branch and leaves Garrus’s growth tied to revenge.

Decision Checklist

• What is my Shepard’s core philosophy? Does lethal payback fit a Renegade or pragmatic leader, or am I building a Paragon who refuses to execute a surrendered enemy?
• Do I have enough Paragon or Renegade points to unlock the Charm or Intimidate options? If not, am I willing to delay the mission and earn more reputation before returning to the confrontation?
• Which emotional outcome matters more to me: Garrus receiving immediate closure through revenge, or Garrus being talked down and potentially carrying a more reflective, merciful lesson into the rest of the trilogy?

Alternatives to Consider

The primary alternative is to talk Garrus down using a Charm (Paragon) or Intimidate (Renegade) option. A successful Charm appeal focuses on the emptiness of revenge and the fact that killing Sidonis will not bring Garrus’s team back; Garrus lowers his rifle and Sidonis survives, often expressing remorse. An Intimidate-based alternative lets you scare or warn Sidonis into fleeing, achieving the same practical outcome while preserving a harder edge. Both approaches can resolve the loyalty mission and keep Garrus loyal if handled correctly, awarding morality points in line with their style. If your reputation is not high enough yet, you can leave the mission and return after completing other assignments, because loyalty missions are not tied to a hard countdown in the same way the main plot is. Finally, some players save the game at the confrontation and reload to experience both outcomes, treating the choice as a branching story beat rather than a permanent dilemma.

Final Recommendation

Let Garrus kill Sidonis if your Shepard is Renegade-leaning, pragmatic, or focused on backing a friend through a revenge arc, especially when you either agree with the execution or do not have the reputation to intervene safely. Stop him if your Commander is merciful, Paragon-focused, or interested in seeing how Garrus handles restraint and redemption. In gameplay terms, either path can resolve Garrus’s loyalty mission and unlock his loyalty ability if the conversation is handled properly, so the decision is primarily about role-play, morality points, and long-term storytelling. For precise dialogue thresholds, outcome details, and platform-specific notes, consult an up-to-date Mass Effect 2 guide or the Mass Effect Wiki before taking the shot.