Little fun fact about the elemental-siblings:
Not only do they represent the elements Water, Earth, Air and Fire but also the seasons. In Hikkundya the seasons are even named after them being Nifiezun(Winter), Tsutieal(Fall), Erapus(Spring) and Ylppochie(Summer)
You may have noticed that there are 2 different designs for Akuro. The left one from the first part and is his original design. The right one is his shapeshifted design and is in the second part on onward. Through the shapeshifting Akuro also gained pyrokinetic abilites