

Q1: What does "the total cards in both players' security stacks" in this card's inherited 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.4 Reppamon EX5-029 C Champion | Vaccine | Holy Beast [When Attacking] By trashing the top card of your security stack, for the turn, when one of your Digimon would next digivolve, reduce the digivolution cost by 2. --- [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.4 Reppamon EX5-029 C Champion | Vaccine | Holy Beast [When Attacking] By trashing the top card of your security stack, for the turn, when one of your Digimon would next digivolve, reduce the digivolution cost by 2. --- [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.4 Reppamon EX5-029 C champion | Vaccine | Holy Beast [When Attacking] By trashing the top card of your security stack, for the turn, when one of your Digimon would next digivolve, reduce the digivolution cost by 2. --- [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.4 レッパモン EX5-029 C 成熟期 | ワクチン種 | 聖獣型 【アタック時】自分のセキュリティを上から1枚破棄することで、ターン終了まで、次に自分のデジモンが進化するとき、支払う進化コスト-2。 --- 【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。