Intact decks (total cards 86):
Almost certainly(safe for vaultdiscards 43 cards):
Death rush+frogs (17 cards)
Bonewalldials+SoSac+Miracle (26cards)
Likely (had not lost since they were last played at least 3 rounds ago):
Water duo (NT, Chrysaora) (19 cards, arsenic might have been discarded, vault discards possible)
Total so far: 62 cards, 24 remaining
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duo is probably gone, unless they kept only fractals
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duo could be salvaged from entropy (~16 cards)
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duo possible (salvage deflags and phoenix)
Mono should always be a possibility (would strain the other decks though)
This is assuming they can manage 50% in-element w/o transmuting.