Colonist // Sole Survivor: Shepard has lost everything, twice. Come out of the unlikeliest scenarios consistently.
This gives them a pragmatic view of survival and a chip on their shoulder for Batarians and Cerberus. Seeing the way people have been mistreated, Shepard goes out of their way to help those that are genuinely in need while mercilessly fucking up anyone who is causing suffering to others. Always betray Cerberus, tell TIM to fuck off in every possible scenario, probably a little prejudiced toward Batarians.
So Paragade, basically. 60/40.
"Lot's of ways to help people, sometimes heal patients, other times kill dangerous people. Either way helps." -Mordin