#4 Kida - Protector of Atlantis (Enchanted) Set: Into the Inklands Printing: Holofoil Increase: +$12.45 Current Market Price: $50.03 With prices spiking for more recent sets Enchanted cards, collectors and speculators are starting to go back to pick up earlier chase cards
That is, you can activate the equip ability targeting the creature Killer Cosplay's already attached to, but that ability resolving won't do anything
Ultimately, as mentioned, I wouldnt hold your breath for any future rule changes regarding Meld

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You can do it at instant speed so you can trigger it in response to a removal spell
It calls into question the distinction I made about moving counters versus removing them and adding new ones, since this black creature is functionally the same as Thief of Blood, for +1/+1 counters at least