Can I use this card's [All Turns] effect to play a purple Tamer card from my trash?
Yes, that's correct.
Jun. 28, 2024
What does "for each card in your opponent's hand, reduce this effect's play cost maximum by 1" in this card's [All Turns] effect mean, exactly?
It means that you reduce the maximum for the play cost of the card that can be played by this effect by 1 for each card in your opponent's hand. For example, if your opponent has 4 cards in their hand, you would reduce 10 by 4, resulting in a maximum play cost of 6, meaning that you can play 1 purple card with a play cost of 6 or less without paying the cost.
Jun. 28, 2024