15. I believe that the second arc protagonists are similer to the first arc. So i'm gonna tell you why.

Clay-Qibli: These two are almost identical as they both want the best for everyone, both are the funny ones of the group, and that Clay is the glue between all of them, so is Qibli! The reason I say Qibli is the glue in the books is because he has keep them together by joking around and being fiercely loyal to everyone in that group.

Tsunami-Winter: This ones a little obvious; they are both good fighters and are usually the first to attack. They are both willing to die for their team or family(Winter the 'Diamond challenge' and Tsunami in the hatchery with Akulet). They are also simaler in the way that both thought they killed their family, well Tsunami really did, but Winter thought he indirectly killed Hailstorm.

Glory-Peril: They are both misunderstood and are very powerful but are hated for it. Glory for being queen of the Nightwings and Peril for having firescales. They are both temped by ex-Queen Scarlet, Glory sleeping and eating pineapple in the sun, and Peril as Ex-Queen Scarlet made her believe that only she can love her. Also they both say the opposite comforting thing, their are also really sassy.

Starflight-Turtle: Both powerful, Starflight in knowledge and Turtle in magic, but both are terrified that if they do something that they will for sure mess up. Both just want to dissapear when it gets rough but they both had to do something when it did get rough, Starflight when he is in the volcanoe(Really its more fear, but he does that on Glory's word) and Turtle tossing his stick to Anemone. I believe that this is the most accurate of all the pairs.

Sunny-Moonwatcher: Both are seen as little and weak, but both hold a powerful title, Sunny as Princess Sunny(Or Ex-Queen Sunny) And Moon as the first Nightwing in generations to have powers. Both do big things, Sunny is finding the Eye of Onyx and Moon is befriending a Nightwing Monster-

"Whoa, whoa whoa, i'm not a monster. I'm a dragon like yourselves... or I guess your scavengers..... whatever. Go live in a rock"

If you really want to you could throw Kinkajou in there instead of Peril but that list would be different, such as:

Clay-Turtle

Tsunami-Winter

Glory-Qibli

Starflight- Moonwatcher

Sunny-Kinkajou

I'm not gonna explain these ones, but feel free to debate on them in the comments and please tell me if you agree or not