Reverse Healing

The next time a source of your choice would
prevent damage to an opponent or creature,
cause an opponent to gain life or cause a creature
to gain 1 or more +1/+1 counters, it deals that
much damage to that opponent or creature
instead. Damage dealt this way cannot be
prevented.
"There is no pain so great as the memory of joy in
present grief." - Aeschylus