Wow, this one is way better! Here’s why:
Pros:
Art style is so detailed and gorgeous
More vivid characterizations & relationships
Immersive
Cons:
Slower paced, so less story
Fewer chapters
Sometimes given too many details
Personally, I prefer this version for both the art and the story. The other version’s art is fine, just very shoujo-generic, so it’s a bit bland.
Also, sometimes this one gives too many details about magic mechanics, but it expands so much more on each character’s connections. We get to see Tobias grow up with Dahlia and how crazily their relationship changed (plus details into how scummy he is). We also get to see the adorable relationship Dahlia had with her father rather than just the fact she had a father and he was a magic artisan like her. In this one, you can really feel the affection between father and daughter, as well as the warmth between friends.
Read this version for a more beautiful, fleshed-out story and read the other for quick plot gratification.