other vampires you control get +1/+1.
when edgar, charmed groom dies, return it to the battlefield transformed under its owner's control.
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edgar markov's coffin
legendary artifact
at the beginning of your upkeep, create a 1/1 white and black vampire creature token with lifelink and put a bloodline counter on edgar markov's coffin. then if there are three or more bloodline counters in it, remove those counters and transform it.