Falkenrath Gorger gives any vampire card the madness text, while Conspiracy Theorist, Containment Construct and Oskar, Rubbish Reclaimer work for any card (though Theorist and Construct do not let you break timing rules the way true madness does)
Cards like Ominous Roost and Secrets of the Dead can generate even more value for doing it
: Target Merfolk creature can't be blocked this turn
Id recommend avoiding the each opponent mode unless itll win the game but across three choices with the other two modes, its not unrealistic to remove three or four permanents with this one card
So I tossed them both in the 9 spot on my countdown, as I value them equally after playing with them
One new keyword ability, which is intended for use with the co-op modes in Illumineers Quest, is Sing Together