Lucy Heartfelia possesses the power to summon spirits from another realm to aid her in her adventures. Among those, she possesses the great zodiac keys which are unique gold keys that summon even more powerful spirits.
FT/S09-027SP-SP is the main combo of the deck. Essentially, if you pay the costs, you can cheat out any level 2 or lower Key (鍵) character from your deck to your field without paying their costs. The deck will focus on finding ways to abuse this effect and spawn some rather overly powerful targets.
FT/SE10-16R 美しき絆 ルーシィ (center)
FT/S09-036U 指輪魔法 ロキ (right)
The targeted spawn targets are probably the ones above. Your ratios are dependent on your choice, but more than likely, your biggest target will be FT/SE10-16R.
FT/S09-031R is a RNG spawner that can bring out any level 2 or lower Key character from your deck to the back-row if she triggers a climax. The cost is rather high, but it is a way of ensuring you have field for the following turn. Additionally, she can pay a stock to spawn out a level 2 or lower Key from your hand for the turn, but it bounces back to your hand after.
FT/SE10-16R is likely your other combo of choice with the climax shown below. She gets 500 power for each of your other Key characters. When she attacks with her combo in play, you can pay the cost to reveal the top two cards of your deck. Then you may add any Key trait characters to your hand.
FT/S09-036U is a generic overpowered beater with a downside if played from hand. Although, this downside can be used to force more cards into memory if needed.
FT/SE10-19C あたしの決意 ルーシィ (right)
Cards like the above are suggested. FT/S09-030SR is a changer that spawns into FT/S09-027SP-SP to setup for the following turn. FT/SE10-19C has an ability that lets it go to memory if the card on top of your deck (revealed) is a Key character upon its reverse. This is very important because a key part of this deck relies upon placing cards into memory.
FT/SE10-22C 六魔の祈り (center)
FT/S09-047U チェンジリング (right)
To accomplish the memory conditions, aside from the two from the block before, cards like the above are suggested. FT/SE10-17C is a drop search that goes to memory upon reverse if you pay its costs. She is very important early card to help grab the other pieces of your deck even though she only searches Magic (魔法) characters (most characters are magic trait).
The two events in the center and to the right accomplish essentially the same goal of grabbing hand and going to memory upon resolution. FT/SE10-22C lets you swap a character on stage and add any character with that trait to your hand. Essentially, you can filter a character that is going to be reversed anyway into another more useful card. FT/S09-047U grabs any character with the keyword, CHANGE, in its text. The targets are less than FT/SE10-22C, but it gives you hand.
In order to establish board dominance, the two cards are suggested to be your back-row. FT/S09-038C does not carry the Key trait and may fail certain check effects, but her secondary ability is just too useful to ignore. Combined with FT/S09-T02TD, you can boost a character by 2500 power which is no small number.
The payoff for having memory are the counters above. You can run up to four copies, so feel free to choose multiple arts if you’d like. They are all the same 3000 powered counter at level 1 if you have two or more cards in memory.
As for the game finishing options, there aren’t too many to choose from. The two cards above are few options for the deck. FT/S09-037U is a level three with a damage reducing ability. Its combo isn’t too impactful, but her memory condition providing hand encore to let her stay on field as continual threat is very nice. FT/S09-034U damages both players when she comes onto the stage. She can be used to just push for some extra damage.
As for other suggestions to include into the deck, it is not a bad option to run vanillas like FT/S09-044C. The deck can be pretty stock intensive, so make sure to run quite a number of costless beaters just to generate stock for your game. Remember that many of your effects require Key traits to activate. Additionally, at the cost of consistency, it is possible to consider running Yellow into the deck with Erza for more field control. Though that is entirely up to you. Do your best and may the golden keys shine in your favour!