10 Most Satisfying Character-Arcs In Star Trek

When we meet Odo in DS9's pilot, he's emotionally distant, clearly beaten down after years of living on the station under occupation. As he settled into a more friendly environment under Starfleet's command, he started to open up to people, especially Nerys, with whom he formed a strong relationship and came to love.

Odo's loyalty was tested when the Dominion, led by his people, The Founders, declared war against the Alpha Quadrant. Throughout the whole conflict, Odo remained dedicated to his friends and assisted Starfleet with developing ways to detect Changeling infiltrators.

At the end of the series, Odo helped end the war by bringing his people the cure for the Changeling virus created by Section 31, and staying on their world to share everything he learned while living with solid lifeforms.