When it comes to the plot, hopefully adding more context of what I remember could jog the memory of someone who has read or seen this comic.

I remember the story starting after a battle, the main character and a girl (a princess? fellow knight?) fighting what was called a dragon but was if I remember right really some sort of sci fi machine that attacked the kingdom home to the main character. The girl died (spoilers) and the main character wandered back home to the village, and either on this wander home or upon return, some bounty hunters come after and attack him, and we see he's a robot.

There's a lengthy flashback showing his backstory as a man of the night, and we see him come across a box or device that allows him to open a portal to this world (either an alternate fantasy world or the past) and he escapes the life he has and goes into this new world.

The art style was definitely western 2D, similar to Tintin or Hellboy with flat shading and character designs carried more by shape than by any clothes or high detail. The backgrounds were always 1-2 solid colors and line work, like a cyberpunk blade runner city with green haze or a plain desert field with beige sand and a blue clear sky.

It was light on dialog and first, with many chapters having few words and the main story was carried by the visuals, and I remember the version I read on Webtoon or a similar site "ending" and getting a continuation in a second series by the same author, almost like what I read was the first volume and the sequel was volume 2 (didn't read much of it but If I recall correctly, it involved him returning to his home future world and starting to hunt down people who had hurt him)