Like Throne of Eldraine, it's one of the eight Commander cards from this set that dont show up in Wilds of Eldraine s preconstructed EDH decks, and it can only be found in either Set or Collector boosters
This card lets you prevent all damage that would be dealt to one of your Creatures for a turn, netting +1/+1 counters on that Creature equal to the amount of damage prevented
To confirm my experiences from testing I thought I would do some maths on the subject which mostly lead to remembering how bad I am at probability
You can double Force Spike a non-creature spell, but for that mana at 1U but can just counter a noncreature outright with Negate
Dont sleep on Author of Shadows, either sure its a ten mana combo, but exiling an opponents Teferis Protection or Heroic Intervention can help you close the game
If you want an alternate win condition for a non-Standard lifegain deck, I recommend Chalice of Life