There was a thing happened while I was playing Spiral Knights..
First I had 100 energy at my other account and then I crafted one of the weapons and armors at my recipe. They both cost me 50 energy each so I got 0 energy left. Then one of my friend decided to play this game so he registered and played at my computer and when he tried to log in at my computer...
He already got 0 energy left instead of 100... So why did this thing happen? Is the game restricting for one player at one computer?
Mist Energy is shared across all unpaid accounts linked to the same computer, to prevent people from having endless amounts of mist energy (which isn't hard to transfer from one account to another, after all, there's lots of ways to turn mist energy into CE or crowns).
You can change an account from 'unpaid' to 'paid' but just once spending 75 cents to buy crystal energy for money, and then that account will have its own separate mist energy pool. For all three accounts to have separate mist energy now, you'll need to spend 75 cents each on two of them.