Two unusually mature siblings with special skills and a tendency to get into trouble, far from home.
Fur color: a light blueish-grey, with black-tipped ears and tails, black fur also on hands and feet.
Height: 5' 1" / 4' 11"
Weight: 107 / 101 lbs
Build: Average, for their kind
Next to nothing, given that their arrival was rather unplanned. They just have what they had in the pockets of their clothes.
Mundane education in a technologically advanced society: They have learned a lot of the basics in school, and know how to apply their knowledge, most of the time. Due to their young age, they don't have specific training in any occupation, though.
Entropy manipulation: For lack of a better term, and because people don't believe in "magic" where they come from, the twins have a special awareness of energy flows, almost like an additional sense, and can manipluate those, not spending energy of their own, but drawing from the energy around them to change its flow. Their frequent use of heat as a source because of its prevalence has lead people to the wrong assumption that their abilities are of a cryokinetic nature, giving them their nickname. They will explain the nature and range of their abilities to anyone who asks nicely, but due to their use of peculiar terms to explain things that are self-obvious to them, such explanation is of limited value. Despite the fact that the energy manipulated is not their own, prolonged use is prevented by physical exhaustion.
Survival: As a typical feature of their species, they are pretty robust, don't get sick easily, heal quickly, and will survive eating from garbage cans - if really necessary.
Alone, afraid and poor: Despite their abilities, and their calm demeanor, they are still far from being adults, and often just hiding their fear. Their most troublesome concern, of course, is if they'll ever find a way home. They are alone in a world unfamiliar to them, without friends, allies or even money.
Basically, the siblings have a lot in common, they both possess an emotional maturity uncommon for their age, and are able to handle themselves in almost any situation. This is probably attributed to growing up with powers that are potentially destructive. They have a tendency to camouflage fear or insecurity with sarcasm, though, even when talking to each other. However, Cassandra is probably the more serious of the two, who usually thinks before acting, while Alan is sometimes still too careless for his own good. He's also quicker to talk and would usually reply first, if both of them were addressed.
The twins grew up in a futuristic, technologically oriented world as part of a respected minority among humans. With powers like theirs being very rare at home, they didn't have anybody to teach them. Trying to practice by themselves, they apparently stumbled upon a portal, and opened it. They have no clue about how to open it from the other side, though.