Artifacts you control have indestructible. (Effects that say "destroy" don't destroy them. Artifact creatures with indestructible can't be destroyed by damage.)
As this enchantment enters, you lose life equal to your life total.
You don't lose the game for having 0 or less life.
If you would gain life, draw that many cards instead.
Whenever you're dealt damage, sacrifice that many nontoken permanents. If you can't, you lose the game.
When this enchantment is put into a graveyard from the battlefield, you lose the game.
Trample
If damage would be dealt to another creature you control, prevent that damage. Put a +1/+1 counter on that creature for each 1 damage prevented this way.
When Vigor is put into a graveyard from anywhere, shuffle it into its owner's library.