Balance Thread

How about Interference Generator?  Three of them can lock out an opponent.  I suppose that's the most obvious one.

Multiple Selection Committees could be quite annoying, though maybe not broken.  Multiple Cursed Warhammers could be scary, ditto for Nate/George for similar reasons (though auto-mill would help).  Multiple Messengite Murals could go critical, but might be expensive enough to be a manageable risk.  Ditto for SHAB Card.  I think that's about all that I would identify as a concern, though I suppose a field full of SWIMSUIT/Silver Arrow would be nasty.

I agree that "not your own uniques" just seems clumsy.  With Nanoreplicator, a 20 life maintenance might do it, or a 10% chance of disintegrating at end of turn or something (with cost reduction, of course, though that presents Mural issues).

For Blank Clone, the nightmare scenario is something like Faritin, where you simply can't let it exist for one turn, lest it do something infinite (even if it can only do a limited number of activations in this case, it could still be pretty crazy w/2 Manamancers and an Author), so it's harder to deal with.

How about something like "Return target monster to owner's hand: Blank Clone becomes a copy of that monster."?  So the Clone is actually acting as kind of a stand-in for that monster.  The cost might be more warranted now, since it also can bounce opponent's creatures (and rescue your own monsters that are in danger of dying).