Enchantment, 2WW (4) If damage would be dealt to you, put that many depletion counters on Force Bubble instead. When there are four or more depletion counters on Force Bubble, sacrifice it. At end of turn, remove all depletion counters from Force Bubble.
Illus. Alan Pollack
The effect does not "prevent" damage, it "replaces" it so the damage is neither dealt or prevented. [Scourge FAQ 2003/05/30]
If you take 6 damage at once, it will replace all 6 damage and put 6 counters on it. Then the second ability will trigger. Any additional damage you take before this ability resolves also results in counters, but once the ability resolves, this card is sacrificed. [Scourge FAQ 2003/05/30]
If you control more than one, each time you take damage you can decide which one replaces the damage, and that one replaces all of the damage. You cannot split the damage between them. [DeLaney 2003/06/14] You decide each time you take damage. Note that damage from multiple sources that happens at one time (such as combat damage) gives one choice, not one per source. [DeLaney 2003/06/14]
Scourge
(Rare)