Sentence:  This is amplified by the common use in a/b/o of the soulmate and <WSD>soulbond</WSD> tropes, where two characters are written as destined for each other on a biological level, resulting in near-irresistible mutual attraction and a special connection. 
Meaning of the word marked with <WSD> tags:  A deep, lasting emotional or spiritual connection between two characters, typically of a physic or magical nature.