During a scene in the trailer you can see someone preform Ice Magic which is interesting topic all on itself but something more interesting is a rat thing you see while the magic is preforming the magic spell. Thanks to The Tree's Apprentice's theory i think i may have a theory on what it is.
I think the Magic in this game is going to be based on Feng Sui which is the theory that there are five elements these are:
Fire,Water, Earth,Wood and Metal:
http://upload.wikimedia.org/wikipedia/en/0/07/FiveElementsCycleBalanceImbalance.jpg
The Metal element can take the form of ice, and the magic being used in the trailer was Ice magic, represented by a rat spirit. There is something that goes
against this theory..The Rat in Chinese mythology is represented by Water not Metal. On the other hand the Rat like the other Chinese Zodiac Animals can be combined with the 5 elements and Water is associated with Ice so it's not a stretch to assume they choose the Rat to represent Ice. This makes me wonder: Will they introduce a Complete Magic Triangle back into the new game with each element being effect and weak to another. Only time will tell.
If you are curious about which element each animal represents:
Rat: Water
Ox: Earth Tiger: Wood Hare: Wood Dragon: Earth Snake: Fire Horse: Fire Ram: Earth Monkey: Metal Rooster: Metal Dog: Earth Pig: Water