The Orzhov welcome you. Please leave your belongings with the Obzedat. They are not yours anymore.
Hi, I'm a european crested tit, and a very small punk rocker!
Re: Do you have to pay a Nemesis Power cost all at ocne?
You can never pay for something over several turns. You can never split the cost between players either.
That is: unless specified.
Cost 7 is a harsh price and is intended to slow you down. But it's not that hard unless it's on your very first turns. You can easily have 7 on turn 3 with the right market.