- "Yep. I'm Sister...Church's twin brother. I came here in a spaceship, that came from the moon. It crashed next to Blue Base, and now I live with Caboose, and the people from the tail section of the spaceship, live on the other side of the island."
- —Yellow Church in Why Were We Here?
Yellow Church is Caboose's twisted mental image of Sister, who Caboose believes to be Church's twin brother. After Yellow Church escapes Caboose's Mind, he eventually ends up on Sidewinder with numerous other Churches.
Role in PlotEdit
Chronologically, in Why Were We Here?, Yellow Church recites Caboose's story about Sister's origins: a space ship that came from the moon. Later, Church entered Caboose's mind to chase after O'Malley and he found Yellow Church. After expelling O'Malley's presence from Caboose's mind by killing him, Church planted a grenade to kill himself with it order to escape Caboose's mind as well, which accidentally killed Yellow Church in the process (who was trying to ask Church an unknown question).
After Yellow Church was killed he appeared next to one of the dead Wyomings and the latter's temporal distortion unit was activated, transporting him back in time to Sidewinder, where he met all of the other failed Churches. When they asked about his plan, he said "Oh man, it seemed like such a good idea at the time." which is the last thing heard from Yellow Church in Have We Met?. It's assumed he's still active in the past.
Yellow Church seems to be less angry and more depressed and apathetic, evidently having been ground down by his time in Caboose's mind. This is demonstrated by him stating that he no longer sees the point of arguing with Caboose's view of the world, despite its massive errors on even the most basic elements of his life. However, Yellow Church also is the most logical of Caboose's mental images, as he acknowledges the difference in the real world and seems to have an understanding who are the other Churches.
- Yellow Church, along with the other Church clones, appears in the special The Best of Red vs. Blue Awards.
- Yellow Church's story about Sister's origins is based on the original premise of the TV show "Lost", along with the reference "the other side of the island".