WHY WAS SHE EVEN ON THE TEAM ????

IF NINA WAS JUST A NORMAL FISH LADY WITH NO POWERS WHY DID THEY PUT HER ON THE TEAM??? This whole time I was expecting her to have some crazy water bending powers but nope she’s just a fish lady, she provided no help the entire time and then fucking died. I loved her but I feel nothing but anger about her death cuz wtf she didnt do ANYTHING.