Void Dragon
7 Force 4 Chi
13 gold
When Void Dragon Destroys a province, the province's controller discards their fate hand.

Oh wait... that card already exists... and is from a different game... sorry, it's just that L5R IS BETTER and all. but anyways, as far as the Magic Card goes...

Behold the Void
1B XX
Sorcery
Give target player X number of poison tokens where X is equal to the amount of extra mana paid divided by two. Any player with 10 or more poison tokens loses.