Do you want a sibling for Storm?
No. I prefer she stay an only child
If yes, from the mother side or the father side?
I would love to see Storm meet one of her cousins or ancestors from her mother side of the family
Do you want her sibling to be male or female?
Female, someone fully invested in the magic side of Storm's bloodline
Older or younger?
Not sure. Older could give Storm an adversary to fight but younger could give Storm someone to train and look after.
And human or mutant too?
Human but with Storm's blue eyes and white hair
If human, what would be the skills/abilities?
Someone with vast magical powers, who has followed the way of the ancient Atlantean magic. A form of magic so old and powerful that her powers are only matched by Doctor Strange. She would possesses the ability to manipulate the forces of magic for a variety of effects, including mind control, illusion-casting, astral projection, the projection of mystical bolts of force, creation of mystic force shields, the removal of spirits from their physical bodies and mental domination of those spirits, healing, and the ability to mentally manipulate the natural environment of Earth and the astral plane. She is able to time travel and can return from death using time travel. In her physical form, she is able to fly and change her shape into that of other people or animals.