Master of the Divine Beasts

Master of the Divine Beasts manga summary: A human girl, a dragon, and a twin brother!? The fantasy romance you've been waiting for! A girl born from a prestigious family. She who loves steel and is loved by steel, Kai Alterion's raison d'être was solely to forge swords. During the talks about suddenly being married, she pulled out her sword and pointed it towards her fiancé! And just like some magnificent fantasy, she became the Master of the Divine Beast.