

Q1: What does "total cards in both players' security stacks" in this card's On Play effect mean?
It means the total number of cards in both you and your opponent's security stacks. For example, if you have 3 cards in your security stack and your opponent has 2 cards in their security stack, the total security cards will be 5 cards.
Lv.3 Kudamon EX5-028 U Rookie | Vaccine | Holy Beast [On Play] If there're 6 or fewer total cards in both players' security stacks, you may play 1 yellow Tamer card from your hand without paying the cost. --- [When Attacking] [Once Per Turn] If there're 6 or fewer total cards in both players' security stacks, 1 of your opponent's Digimon gets -2000 DP for the turn.
Lv.3 Kudamon EX5-028 U Rookie | Vaccine | Holy Beast [On Play] If there're 6 or fewer total cards in both players' security stacks, you may play 1 yellow Tamer card from your hand without paying the cost. --- [When Attacking] [Once Per Turn] If there're 6 or fewer total cards in both players' security stacks, 1 of your opponent's Digimon gets -2000 DP for the turn.
Lv.3 Kudamon EX5-028 U rookie | Vaccine | Holy Beast [On Play] If there're 6 or fewer total cards in both players' security stacks, you may play 1 yellow Tamer card from your hand without paying the cost. --- [When Attacking] [Once Per Turn] If there're 6 or fewer total cards in both players' security stacks, 1 of your opponent's Digimon gets -2000 DP for the turn.
Lv.3 クダモン EX5-028 U 成長期 | ワクチン種 | 聖獣型 【登場時】お互いのセキュリティ合計が6枚以下なら、自分の手札から黄のテイマーカード1枚をコストを支払わずに登場できる。 --- 【アタック時】[ターンに1回]お互いのセキュリティ合計が6枚以下なら、ターン終了まで、相手のデジモン1体をDP-2000。