So, here’s the “inverted colours” image of our character wearing Church’s armour.

And here’s another image (THe yellow is on the door behind him, this isn’t Wash.

FInally, we have this image, which shows the Wanted list.

The top row shows Sarge, Grif, Simmons, and Donut.

The second row shows Lopez, Caboose, Church, and Tucker.

The bottom row shows Carolina and Wash.

Wash is in his grey armour, and is separate from Church. So this isn’t them thinking that Church is alive because Wash was using his name and armour. Given than Hargrove is likely orchestrating this, he probably knows the state that Epsilon was in prior to the end of Season 13, and Epsilon introduced himself to the galaxy as Epsilon, not Church in his broadcasts.

So… who is this mystery Church?