So wait, you're telling me I could just be walking down the street, minding my own business, when some jerkass wizard from another universe merges our realities or whatever to heal my doppelganger? I'm out 6 HP because of some guy who doesn't live in my universe and I don't even like got hurt?

I'm imagining as a consequence to doing this all the time, eventually the wizard is going to have a class action lawsuit against them from all the innocent bystanders they've hurt. And just imagine the legal complexity of serving all these suits across different universe' legal codes. This wizard's going to be bogged down for an eternity in the courts.

In all the multiverse, there's got to be someone who specializes in parallel-universe case law. A Parallelalegal, if you will.