I was thinking about local co-op, but the issue is the same. You could use that sword enemy as a place-holder art for the player and maybe add for example a green circle below, on the floor to identify the player from enemy, later maybe add direction sprites (look from the side, look from the back).
P.S. Ascend-hard-pacifist done! Now in progress descend-hard-pacifist. (invisi-ring plus map-ring is a great combo for pacifist. Also not having powerful kicks trait helps to move enemies away from doors.)
You: *breaking crate by pushing it into enemy or enemy into crate or simply loudly opening a crate, or kicking enemy across half of the map*
Enemy: This is fiiiine...
You: *opens one squeaky door or not oiled properly gate*
Enemy: You dare challenge me mortal!?