its a rule in the lore of that game, not the game itself. http://mtgsalvation.gamepedia.com/Planeswalker's_spark... wut? ... The ability to keep up with the M:tg rules, and know what a planeswalker spark even is.
Damn straight. You wouldn't have to know her yet--it'd be like a way to find your match if they notice you naked.That wouldn't be useless IMO