Voyager (Changeling)'s Links
Voyager found Leech in a quarantined city filled with strange, mutated people. When Leech escaped as a direct result of Voyager's presence in the area, they decided it was their responsibility and took it in for at least a little while.
Now, after at least a year together, Voyager is almost like a parent to Leech and has come to care greatly for it's well-being.
Raising a child with such specific and special needs comes with challenges, but Voyager has always accepted them wholeheartedly and is honestly unaware that raising Leech is significantly different in any way from raising any other child.