1. I'm not sure which image your referring to for Mezz. Terminology: "sprites" are the ones with transparency, and more precisely, mostly the ones in "sv_actors" (pardon, I was calling it "sv_characters" before) and "characters". If you mean the one with him bent over in the cage, that's simply a scene you may not have gotten yet. If you mean any of the images with his head back in the actual sprite sheets, those are the reaction image to him being hit during battle.
2. As for Mahir: the image you're pulling for Diezel is being taken from the game itself. The image you're referring to for Mahir was posted HERE, to Itch, during initial discussion and production of the game. I added the background to make the outline clearer, as it wouldn't look as good with transparency against the solid black of the game page. The screenshot is of course in-game, so it uses the actual transparency image.











