i pray to never rest in peace.

Icewings have blue blood, this is common knowledge yes. But the effects of this are not. Blue blood actually helps with living in cold environments which makes sense but it also allows survival in extremely low oxygen environments. So theoretically Icewings can probably fly even higher than Skywings since they can survive in the thin air of the upper atmosphere. No Icewings have tried to do that yet because it's incredibly tiring to fly that high with their wings but still. It could happen.

Not only that but blue blood helps the immune system against bacteria. So Icewings are basically immune to most illnesses caused by bacteria, but I like to think that this would make them more susceptible to viruses that the other tribes treat like the common cold (this would probably also be due to their isolation)

In addition, due to their incredibly light color they are probably amazing at hunting fish and diving for prey. This would work similarly to how white grizzly bears are more successful ambush fishers because the fish don't see the shadow of the bear due to light reflecting off their fur. Not only that but Icewings have serrated claws which are perfect for fish. This would work similarly in the sky and could possibly even work to blind prey with their reflective scales.

Despite their tendency to prefer cold environments Icewings don't actually overheat in the desert/sun easily. Their light colored scales would reflect the sunlight, like how blonde people's heads don't get as hot in the sun as brown or black haired people. Just imagine Moon and Winter in the desert with Qibli and Moon is suffering in the heat with her black scales and she feels bad for Winter who must be suffering far more than her... and he's just fine, mildly annoyed by the sun in his eyes while no one can look straight at him because he's like staring at a sheet of white snow on a sunny day (very bright if you didn't know). The only reason he disliked the rainforest so much was because of the humidity - the tundra of the Icewings Kingdom would be incredible arid.

Finally the most fucked up thing about Icewings: instead of body heat they somehow emit cold. Which is impossible due to cold being the simple absence of heat and therefore being unable to be "emitted" (I am not explaining thermodynamics but it's the reason the outside of your freezer/fridge might get hot, it's actually absorbing the heat). So, they must therefore be absorbing and retaining heat in their bodies. That's the real reason they can survive in such cold places - their body retains heat at a much higher rate than the other tribes. The reason the air feels cold around them is because they are absorbing all of the heat around them into their body. This also is compatible with frostbreath, the Icewings absorb as much heat as possible from an organ in their throat, making their saliva freeze, creating frost breath. This is also why they must be in a cold enough place to do it - if they do it somewhere too warm then they will actually over heat as they absorb way too much heat as opposed to getting frozen from over usage. (This intense control over their body heat would also lead to some interesting effects when it comes to fevers) I don't really have a scenario for this except maybe Clay takes the internal temperature of an Icewing student as a part of a check up and actually freaks the hell out at how high it is, having expected a lower number to the averages of other tribes.

Some less scientific and more silly example of weird things Icewings can do in my mind:

Their extra "horns" shaped like icicles? They're actually just really big scales and will fall off and shed after a while. Imagine one of Winter's "horns" is loose and it's annoying him so in the middle of breakfast he just reaches back and pulls it off. The rest of the winglet starts thinking that Winter's dying and are freaking the fuck out, meanwhile Winter has like eight of these hidden in his bed.

Their long tail is not prehensile but they can grab things with it by whipping it around an object and may be able to use it as a grapple weapon. Qibli wanders off from the group and is stopped by a thin white tail winding around his arm and dragging him back.