Short of Perfection

As an additional cost to casting this spell, discard
two cards.
When Short of Perfection enters the battlefield,
create"Umbilical Cord", a colourless artifact
under target player's control. So long as
Umbilical Cord is on the battlefield, whenever
player controlling Umbilical Cord gains life, you
gain that much life as well, that player also loses
that much life as well.