the powers of a yuki will differ slightly based on it's gender. The strength of a Yuki's powers will also depend on its age, older Yuki are stronger and have more control.
male:
a male Yuki's powers are more combat oriented as well as more focused on ice then snow.
-Their most commonly used ability would be 'Ice blade' in which they fashion a blade from any snow or ice in their vicinity, if in dire straits they can use water and freeze it but it won't be as effective.
-A strong male Yuki can summon a minor storm front, which can lead to snow or rain.
-Male Yuki can temporarily give life to an ice creation (think Olaf from frozen but ice). To do this the Yuki effectively takes a piece of his soul and places it in the creature, temporarily weakening his own powers and body. When the creature is destroyed or the magic dispels that strength is returned to the Yuki.
-Male Yuki do have minor control over ice itself. In a very icy area they can morph the ice around them, attacking with their very surroundings.
Female:
Females' powers are similar but based more on defense and more focused on snow.
-Female Yuki have the ability to call snow storms, though the storm is proportional to the Yuki's power. A child would create a single cloud, an ancient could cover the entire mountain in a blizzard.
-Similar to the male's 'ice blade' ability, female Yuki can solidify the snow into a sort of spear that they use if they are forced into actual melee combat.
-Yuki can create illusions from snow, they can look like a house, or a person, or even (for very Yuki) entire towns. But the effect is only visual and auditory, there are no smells attached to the illusions and if they are examined to closely you can tell that they are not real (though the strong the Yuki and the more concentrated it is, the harder it is to tell) and there is no actual substance to the illusion, if touched it will crumble away as snow (for larger illusions, it will crumble where touched and generally the Yuki will release the rest of the illusion). This is often used as a tactic to get enemies lost in the snow.
-A powerful Yuki can cast a cloud of snow over a town that puts the inhabitants to sleep. A less powerful Yuki can put maybe a handful of people to sleep, though usually they are not capable of even that until they reach maturity.
Both: the two genders have a few abilities in common
-they have an ability to charm living creatures, making them more willing to listen to the Yuki. Strong-willed people and races are less likely to be effected and it can't effective mechanical creatures at all.
-Yuki also have the ability to go incorporeal for a short period of time, generally to give themselves a chance to run away from an enemy they can't defeat, or to scare someone.