I was reading this manhwa recently called A Fairytale For The Demon Lord and was surprised at the quality of the art for a weekly release.
It actually started as a webcomic but it turned to be longer than originally planned. Although its not groundbreaking story, its nice to read a knight saves the princess story (even though the princess is super strong in this case). It's a very new manhwa so the plot hasn't developed much but it already gives some hints.
The original site for the web comic can be found here.There once was a princess who fell for a curse. Countless times have a knight come in vain attempts to save the poor princess. They all failed, killed by a demon. When a knight finally comes to defeat the demon, there appears an adventure never before predicted...