Card City Nights

The easist way to get a 9 card/10 damage combo is to use Bob's Ship. You can knock both out at once by using Attack cards with many directional arrows paired with cards that do extra damage on Attack Combos (e.g. Ultra Fishbunjin 3000, Skull Buni, Haja, Bear Miner, etc.). You can get a copy of it from the Martian booster packs from figthing Bumptious Miner at the Bear Mine.

Construct a 25 card deck with Bob's Ship and multiple attack/Neutral cards with many arrows and head to the ΩMega Mall to battle Loafer. She hardly creates combos and doesn't often attack or disable your cards, so it should be fairly simple to construct a large combo on your board. It couldn't hurt to pack a Health Potion or two just in case.

Arrange your 8 cards around the perimeter of the board first, making sure to avoid accidentally creating combos before placing Bob's Ship in the middle connecting all 9 at once. If you're doing this with multiple +1 damage on Attack Bonus cards you should be able to do 10 damage as well.

The easiest way to win in 5 turns is to stock a deck up with purely Attack cards including ones that deal bonus damage on Attack Combos (e.g. Ultra Fishbunjin 3000, Goddess of Explosions, Skull Buni, Haja, Bear Miner, etc.). Mix this up with multiple arrow Neutral cards to combo them together and it shouldn't be too difficult to deal 7 damage with 5 cards.

Head over to the ΩMega Mall to battle Loafer. She hardly creates combos and doesn't often attack or disable your cards, so you should be able to drop your 5 cards without much fuss.

The Card Gods are 4 extra battles after the end of the main story, each of which uses a special Beta card that you receive for winning.

As a general strategy guide for completing the game and facing the Card Gods, it's extremely helpful to re-do fights for booster packs. Some rare and uncommon cards are extremely useful and you'll have a much easier time progressing with even 1 or 2 copies of these cards in your deck. Each booster pack battler should be pretty simple to grind at whatever stage you are in the game, so I'd highly recommend sourcing out some powerful cards from them before continuing in order to make the rest of the game much simpler with overpowered ability cards.

I've found that adding any defense cards in a deck is a waste. Being aggressive with disabling enemy cards and forcing them to fill their board seems to be the best option. Stack your deck with quick pairing attack and disable options with some revives and focus on rendering your opponent useless. Otherwise, attack their health. Plenty of cards will allow you to prevent taking damage or will give defense without needing to create Defense combos.

Cards Overview: https://steamcommunity.com/sharedfiles/filedetails/?id=229659417

Here's a personal list of very useful cards worth collecting and adding to a deck. !! = Busted Good ! = Very Good

!! Iji DX (L) - Legendary card obtained through story progression. Heals 1 every turn and prevents all damage while active.

Ittle Dew booster pack - Loafer @ ΩMega Mall
!! Itan Carver (R) - Immediate revive upon placement and a double Revive icon that will let you revive a second card when paired with any one other card.
! Ultra Fishbunjin 3000 (R) - Versatile double Attack icon card that will either boost your attack damage or can be quickly paired with any card for an easy disable.
!! Health Potion (U) - Quck drop and revive a random card.

Ittle Dew Baddie set - Stoneface @ Cave
! Jenny Deer (R) - Double Revive icon card that will give +2 defense as a bonus when paired.
! Jenny Bun (U) - Useful Neutral pairing card that gives +1 defense when placed.

Jam-Packed Set Hovering Sheet @ Haunted House
! Mc Cluck (R) - Very solid pairing Neutral card

Healthy Weapon set
!! Anna Ban (R) - Instant disable on placement. Breaks up enemy combos super easily.

Fate of the Earth set Tall Skater @ Skate Park
! Iji (R) - Double Revive icon card that will give +2 defense as a bonus when paired.

Martian set
!! Bob's Ship (R) - The ultimate Neutral pair card. Arrows in all directions.
! Anti Muri (R) - Dual Attack/Defense icon card that can easily pair with 1 other Neutral/Attack card for quick disables.

Alchemy Cards - These can be created by talking to the Salaryman at the Science Lab.
!! Brickpocalypse (R) → Garden Gnome + Cat - Like Anna Ban, but better. Instant (random) disable on placement and removes itself.
!! Zero (R) → Drone + Drone - Extremely powerful card. Multiple arrows and can instantly pair with one other attack card and rotate enemy cards to break up combos and disable any other problem cards.
! Stack of Pancakes (R) → Pancake + Pancake - Pretty good card that can double as a passive deck burner.
! Metal Mark (U) → Mecha Santa + Mark OR Snäke + Mark - Dual Neutral icon card that can be paired quickly with another attack for easy disables.
!! Young Lichious Turnip (U) → The Lichious Turnip + Flopflop - Like a budget Iji DX. Prevents all damage.