They are sentence fragments. They are grammatically incomplete.
They also are not meant to be read rationally. They are intended to reflect the emotional turmoil of falling in love. To be read as intended, they must be read as essentially appositive phrases in the preceding sentence. Trying to make sense of what I see as over-written balderdash, it seems to be trying to say
when two beings [presumably human] need [the author means “yearn”] to become one emotionally fused being [that’s not what “ductile” means, but he is on a roll], so that he is me and I am him.
It is decipherable despite the sentence fragments and misused vocabulary, bur deciphering it is complicated by the fact that it does not make much sense. Of course, the narrator is busy having sex with a peach while writing so sense is something he may have scant access to.