I have two cards that I wonder about.
First up is the Galapago Card.
For the description it states that it adds a chance of Apple, Banana or Carrot Juices each time insect monsters are killed. Also juice items restore %50 more HP. I'm guessing maybe this does not apply to Grape Juice? I tried it but I don't think I see a difference. Perhaps it's not included (and also perhaps because Grape Juice is for SP). I'm not sure if the effect stacks if you have two of those using the included juices.
The second card is about the Mimic Card.
For the description of this card it says that it adds a chance of gaining "Old Blue Box" each time a monster is killed. Does this stack too if I have two Mimic clips?
I guess for that matter too, throw in the Spring Rabbit Card for card effect stacking. I believe more vit will lead to higher heals. Like using GJ with high INT seems to restore more SP per usage.
Edit again:
Does 2 Bloody Shackle Balls Stack with one pair of Shackles? O_O