Ok, lets fill this thing systematically.
We have 500-26+12=486 cards (if I recall right).
That means we have to take at least 243
cards
Of course we will need a lot of water pillars and pendulums (at least 8*12 = 96 for the first round)
To play it save, and prevent early converting, I think we should get at least 125-150 pillars/pendulums
That leaves 100+ (as we don't have to take 243 cards of other elements) other water cards to be filled.
First a look at the water cards:
24 toads, they are way to usefull to leave out
24 dragons, the same
18-24 chrysaora, really usefull too
12 mind flayer, situational but usefull
12-18 crawlers, good filler cards, especially upgraded
18-24 squids, because they are awesome
18-24 freezes, for their epic slow down effect
18-24 ice bolts, they even have different possible uses
6 floodings, they can be usefull, but you only need one to make it work, and they are situational
12 tridents
12-18 ice shields, we need them
12-18 steamies, they are usefull, but need dedicated decks to be able to use them in bigger numbers
6-12 nymph tears, because of the nice decks they can make
0-some mark of water and nymph queen, as I don't think most people have them, meaning they would be useless for most people
Other cards we might need:
dimension shield
quint
PU
lightning?
shockwave
wings
fog shield
steal
liquid shadow?
poison
arsenic
bonewall
earthquake
shrieker/graboid?
EA
pendulums/pillars
discord
nova
BE?
mutation?
deflagration
immolation
phoenix?
momentum
acceleration
gravity shield?
forest spirit
adrenaline
heal
miracle
reflective shield
morning star
sanctuary
reverse time
btw, could everyone post the nymphs and marks they have?
I will start: