Kirsi

When the three siblings are captured by humans and taken to some lab, they escape but find out there in the Arctic tundra and no bat can survive there until they meet a big drove of Arctic hares and find out two bats live in the group, and one of those bats is Kirsi, the hares said they found the two of them separately but around the same age, they were only pups when they found them so the bats only know how to act like hares, they have strong legs and wings to run with the rest of the hares, when the bat siblings find them and live with the hares until they get home, Serenity teaches Kirsi about being a bat and they form a bond together. Serenity and Kirsi both talk about being unable to fly, but Kirsi just never learned and unlike Serenity she has a thirst for wanting to learn more about being who she is and wanting to one day learn to fly so high she can see above the white icy lands of the tundras