Vivisurgeon's Insight
Sorcery
"Experimental Log 290: Leaving the subject's pain receptors active appears to yield an unprecedented combination of incoherence and hyperawareness."
Rulings (6)
To proliferate, you can choose any permanent that has a counter, including ones controlled by opponents. You can choose any player who has a counter, including opponents. You can't choose cards in any zone other than the battlefield, even if they have counters on them.
If a permanent ever has both +1/+1 counters and -1/-1 counters on it at the same time, they're removed in pairs as a state-based action so that the permanent has only one of those kinds of counters on it.
An ability that triggers "Whenever you proliferate" triggers even if you chose no permanents or players while doing so.
Legality
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