I remember the OM2 picture, that's a screenshot from early in the English translation where the font was being replaced from Japanese, and the hex values didn't match the correct font characters.
The "muna" translation wouldn't apply here, since we're dealing with the original Japanese version. "xT " is the original garbage, if that makes sense. I should point out the Japanese version has a few English letters like you see there, but not all. It's pulling the next 5 bytes from where it's getting the character names. Just like the garbage graphics in battle - it's getting the next 5 bytes to use as the PC sprite data. In that situation the next 5 bytes are actually the start of the NPC sprite data. The game is actually displaying Melchior, but it looks like garbage because the game isn't decompressing it.
There isn't any evidence there was ever supposed to be an 8th playable character. The solider map graphic can be loaded as a party member on the overworld because it's the data directly following the original 7 (like the example above), and is stored in the same compressed packet. BTW, I investigated that a while back and found it wasn't loading the palette to where the PC palettes are stored in memory. IOW, it was treating it as an NPC.
It appears the map soldier was meant to block access to certain 600/1000 AD areas (like the overworlds in other RPGs) before you were meant to go there. The only 2 completed frames seem to suggest that, so that the character could do the standard "walk while standing still" animation.
