This enchantment enters with X echo counters on it.
You don't lose the game for having 0 or less life.
At the beginning of your upkeep, sacrifice this enchantment if there are no echo counters on it. Otherwise, target opponent may choose that for each 1 damage that would be dealt to you until your next upkeep, you remove an echo counter from this enchantment instead.
: Two target players exchange life totals.