In comparison, Sterling Keykeeper isnt totally uneconomical but its definitely on the expensive side for what it does, demonstrating the additional value the set designers placed on crimes
I was close to making Courtesan Thais #1 on this list for the fact that she ruins games for your opponent
While it only affects the creature type you name, it provides cards when those creatures ETB or attack
Seifer's great as long as you get a few triggers out of it
One of the standard payoffs for opponents drawing extra cards is you drawing an extra card, which you can do with piggyback cards like Faerie Mastermind, The Council of Four, and Trouble in Pairs
In that sense, he's a character that is approachable to both old and new fans, and the fact that so many people keep coming to me asking for 'Sephiroth