Re: How to Build : a Lucky Stealer Power
To me sucking off someone else's luck would be: if they had Luck, it would be reduced and yours would be increased. If you happen to take more than they have to start with, they end up getting Unluck as the balance.
If your character has no Luck of his own, or even if he starts with Unluck, have it played up about what happens when he starts siphoning.