I apologize in advance for my English & grammar as it is not my first language.
I've been using your website (http://hex.tcgbrowser.com/) for some time now and it is very useful and convenient in sorting out my cards/deck collection. I appreciate the hard work, time and skills you have put into this excellent website and thank you for it.
To add more convenience in using your already excellent website, I would like to suggest more features to it, which is completely at your behest.
Providing themes for the website would be very well received.
Feature request for cards section:
1. Introduce a [Sub Type] Filter with the values below.
I would like this filter to work only on the Title and NOT on the Name/Description of the Card.
Abomination
Airship
Angel
Arborean
Avatar
Bard
Beast
Bird
Blob
Bones
Caribaur
Chaostouched
Chest
Cleric
Concubunny
Construct
Coyotle
Cromag
Demon
Despair
Destruction
Dingler
Dinosaur
Dragon
Dwarf
Egg
Elder
Elemental
Elf
Engine
Enlightened
Factory
Fae
Faerie
Feet
Forge
Gargoyle
Ghoul
Giant
Gloves
Gnoll
Goblin
Great
Griffin
Hag
Harpy
Head
Hero
High
Hope
Horror
Human
Hydra
Iljuni
Illusion
Imp
Insect
Insight
Junk
Justice
King
Knight
Kraken
Lust
Mage
Malice
Manifestation
Manti
Might
Minotaur
Mutant
Necrotic
Nibblin
Ogre
Orc
Pegasus
Pet
Phoenix
Plans
Plant
Present
Prince
Princess
Queen
Ranger
Robot
Rogue
Salvation
Satyr
Sensei
Shapeshifter
Shin'hare
Shroomkin
Skeleton
Slave
Sphinx
Spider
Spirit
Squirrel
Standard
Stormling
Tentacle
Totem
Transcended
Trap
Trinity
Trinket
Troll
Undead
Unicorn
Unique
Vampire
Vennen
Voidtouched
Wall
Warlock
Warrior
Weapon
Wisdom
Witch
Wolf
Woolvir
Worm
Yeti
Zombie
2. Introduce a [Cards] Filter [Dropdown] and put the PVP [Checkbox] and PVE [Checkbox] filters as values in the dropdown. Add one more value [Banned] in it.
Hence the new [Cards] filter [dropdown] will have 3 values (PVP, PVE, Banned). I assume the "All" options are implicit for all the filters and hence will be available.
So far I'm aware that [Curse of Oblivion] and [Subtle Striker] are banned in PVE.
[Titania's Majesty] is banned in Constructed PVP. But still playable in limited any time you open one.
It will also be helpful if you could also display dangerously (should not go unnoticed) the Banned information in the card display mode.
3. Introduce [Socketable] Filter with (Minor, Major) values. I'm aware that, there is already the socketable keyword in the Keywords Filter, but still requesting this filter for convenience.
4. Update the [Collectible] Filter [Checkbox] to [Tokens] Filter [Dropdown] with (Yes, No) values. "Collectible" name is very confusing, "Tokens" are easy to understand.
The reason for introduction of the Tokens filter is because, currently I cannot view the Tokens only. All the other cards are also listed along it.
5. Update the [Released] Filter [Checkbox] to [Released] Filter [Dropdown] with (Yes, No) values.
Same reason as above.
6. I'm not sure how to achieve this, but still leaving it upto you.

Can you Update the Shard Filter to include a new option value of (Full Threshold).
Basically it should list cards with skills like [Sepulchra Bonewalker], [Forgotten Monarch], [Eye of Lixil], [Lixil, the Deathless Gem], etc...
7. I'm not very sure when the [AND | OR] operators are applied. But In some scenarios I would rather like to search for prismatic cards of Shard Types Blood & Diamond only.
But neither the Prismatic option works as it list all the other shards types along with it and nor does selecting the Blood & Diamond Values works as it also displays single Blood or single Diamond cards.
I hope you understand what I mean.
Currently when I select the Blood & Diamond values from the Shards Filter the [OR] operator is used, but I would like to use the [AND] operator in some cases. How to implement it is upto you.

8. Rename the Cost Filter to Threshold Filter.
9. Introduce a new Cost Filter that can filter based on Platinum or Gold Prices.
Feature request for decks section:
10. Introduce a new [Champions] Filter for Decks. The Values must be all the Champion's names. Also one additional value of (No Champion).
11. Introduce a new column Favourites in the (Shared/All) deck sections. It should dispay a heart icon in the row of a deck which I have already Favourited.
The ones that I haven't favourited should be blank.
12. Identify Rated decks in the (Shared/All) deck tabs while browsing. I think you could provide a green/red background/border for the row, I rated +/- respectively.
13. Notification if any favourite deck or rated deck is changed/updated. Would prefer the notification to be in the website/forum/PM itself and NOT in personal mail.
14. When I browse decks and see the missing cards section, It displays that AA cards are missing. Now I don't have AA cards, but I do have the Regular Art cards for it.
So could you include an option/setting to replace AA Cards in deck missing cards section with Regular cards. (Though I would like to have AAs but curretnly they are too costly to own.)
15. Introduce a new [Self Rated] Filter in the deck section. It should contain 3 values (Positive, Negative, Not Rated). I think this will work only when Logged in.
Bugs:
16. Tournament/Constructed decks are also displayed in shared decks section. Would be very nice to see only user shared decks in this section and not constructed decks.
17. Time Bug card doesn't show equipment details in the card display mode.
I apologize in advance for any inconvenience brought to you by this.
Everything mentioned above is only being presented for convenience purposes, and is solely up to you to decide/finalize its implementation.
Everyone please feel free to discuss/suggest improvements to these features.