Some more things to consider in relation to our vault.
Even if kept 5 Light Pillars from our 3 4 losing decks, we'll only have 40 34 Light Pillars in Round 5. That's only good for 4 3 stall decks, or 5 4 non-stall decks . . . maybe.
Viable decks left:
Water Stall- Kill with MS+Ice Bolts or deck-out; stay alive with Ice Shield
Earth Stall- Kill with MS+Dragons or deck-out; stay alive with Titanium Shield
Life Stall- Kill with MS+Dragons; stay alive with Thorn Carapace, Druidic Staff, Heals
Aether Stall- Kill with PU+MS; stay alive with Phase Shields
Death Duo- Kill with Mummies, Poison, and Arsenic
Air Duo- Kill with FWs+Pegasus; no Fog Shield though
Maybe keep cards (depending on what we salvage):
5 Obsidian Pillars, 5 Amethyst Pillars, 2 Wind Pillars, 7 Momentums, 4 Deflagrations, 3 Purifies, 3 Floodings, 4 Freeze
Throw away cards:
7 Unstable Gas, 5 Flying Weapons
Edit:
Ok here's my thoughts, we can try to maximize our light cards to keep more people playing or we can maximize useful cards and give the few people left playing (and eventually just xdude) as many options as possible. What do you guys think? I think I learn towards giving the last couple players as many options as possible. That way the enemy doesn't know exactly what deck we're gonna play.