Wrex

It still haunts me that there are large swaths of Mass Effect players who never saw Urdnot Wrex fighting Reaper forces on his home planet of Tuchanka and proudly proclaiming “I am Urdnot Wrex, and this is my planet!” Wrex is the first possible casualty of Shepard’s war against the Reapers (RIP to Jenkins, who dies no matter what), and whether he lives or dies depends on whether you’re able to talk him down from a standoff.
When you first meet him, Wrex is a jaded bounty hunter who has lost all hope for the Krogan race. But when it becomes clear that there’s a possible cure for his people’s sterility on the planet Virmire, a sudden jolt of inspiration strikes. Is there a future for the Krogan that doesn’t end in wasting your life as a mercenary sent out to die, or in thousands of stillbirths? But this cure is being made at a facility that is a threat to the galaxy’s continued existence, so it’s gotta get blown up along with the rest of it.
Convincing a man who lost all hope for his people that you must destroy a key to their survival is no easy task, and if you can’t get him to stand down, he will meet the wrong end of a bullet. But if you can convince him, he appears throughout the rest of the trilogy as a radical clan leader seeking to usher the Krogan into a new era. Wrex becomes an advocate for the Krogan people where he was once expecting them to burn themselves out to extinction. Without him to help guide his people, the Krogan could have gone down a very different, destructive path.
Luckily, I never see that future because I am a good friend who he will listen to. The rest of y’all stay safe, though.