Responses
Tsundere Eliza and the golden retriever puppy energy Carl is my bread and butter couple cause they fight in front of the others but so sweet with each other when they are in private. I love how wholeheartedly Eliza supports Carl business venture while Carl continuosly proves himself to be the best person for Eliza ╥﹏╥

Carl Thomas X Eliza Hergin
Celia Zerdinger X Abad Lewalin
Wareden Tyden X (I forgot but she is the Guild Master, older)
Duran Moria X Nella
Reese Zerdinger X Torua
The rest just fawning over Leo Flov/Kyle. There's Chen Xia, Elena Geron, Lil, Chelsea, Iliyana (not sure if it's romantic), Chloe, Lysinas, Luna, etc.
But, my hunch, even if the great heroes resurrected through hero records, Kyle would choose Lysinas. Because no matter what, only things related to Lysinas can shake Leo/Kyle to the core. So, if he need to take someone as wife, it would be Lysinas.