Seems like a cool idea as long as the shuffled-ability creatures are not considered mutants (another passive).
Otherwise it'd be a good idea to remove the selection part.
The only downside is see is that it might make turns take longer in pvp because you'd have to scan
over each card to see what the passives are.
Insta'-killing creatures every turn for 2
'might' also be a bit OP. Perhaps if the target creature/creatures
became poisoned instead?