When i opened my acount on my laptop my mist energy was full then i logged off. When my friend opened his acount on my laptop he crafted a needle shot then logged off. When i opened my acount again my mist energy was all gone. What in Cradle happened ?!
Free accounts on same computer will share energy.
In other words, your friend used all the energy of your computer (different accounts doesn't matter).
Don't share your computer. Or get a paid account.
http://wiki.spiralknights.com/Energy_FAQ