Both stories involve the demon lord ML who is a vessel for all evil/malicious energy and the goddess FL who must restore balance of good/evil in the world. So relationship dynamics are similar - yin and yang, they-are-each-other's-half kind of dynamic. However, while TTJ and YXW are enemies at the beginning, ZYZ and WX from Fangs of Fortune start as companions.
CDL is also in both dramas - as the villain in TTEOTM and FL in FoF.
Finally, both dramas place thematic emphasis on the concept of the butterfly dream.

Although completely different genres and contexts, the dynamics between the leads are similar (slow burn, enemies to lovers). FMC in Call it Love and MMC in LoN both seem "unhinged" and cold hearted at the start. Both are also intent on their revenge above all else, but gradually open up their hearts to love. Both series are angsty in their own way, but relative to each other, I would recommend watching Call it Love after LoN as a comfort watch. Also, the male leads are those tragic, miserable type characters that audiences can't help but want to pity.