Interesting idea, Tiridia. A Scroll of Blight that allows you to blight a region in some manner, either instantly, or by accumulating points over a period of time. But let's skip the healing part. 
What worries me about that kind of thing, though, is how many realms/players would organize a vigilante attitude toward the scrolls. i.e. organizing alliances/groups to punish anyone who uses them. You can see some version of this with the monster/undead scrolls.
Perhaps, to make it more interesting, you could make them "30 second bombs". Every turn they count down by one, and when they hit zero they activate, blighting the region they are in. Make it a "reverse capture the flag" kind of thing, maybe. Have the bombs announce the remaining turn count to the entire region (or current/adjacent regions, like the "RP event" the GM characters can use). That way you can see if someone is sending one your way, and attack the carrier. If you wound the carrier, they drop it, and you can pick it up and carry it somewhere else. You'd know who was sending the bomb after you, and could take appropriate retaliatory action. I'm sure we could come up with a convincing RP basis/explanation for them.
Zap an island with enough of these, and you'd definitely knock down the inhabitable area. You could control exactly how much you reduced the land area by controlling how many of them you released onto the island.
This
could be a huge amount of fun. A 30-day timer that announces every turn, to its current region and all adjacent regions, that the bomb is in keplerville, carried by Evilstan. Infiltrators would swarm Evilstan, and if he gets wounded, the bomb drops and gets picked up by another player in the region (random, or make it appear on the action menu). The bomb stays quiet for 2 turns, to give him a chance to get away, and then starts announcing again.
