


Q1: Can I activate the "when an effect trashes this card from the security stack" effect when this card is revealed from the security stack or when searching/looking at this card from the security stack?
No, you can't. You can only activate the "when an effect trashes this card from the security stack" when this card is directly trashed from the security stack.
Revelation of Light BT15-092 U When an effect trashes this card from the security stack, activate this card's [Security] effects. [Main] Search your security stack. You may play 1 yellow level 4 or lower Digimon card among it without paying the cost. Then, shuffle your security stack. If you have a Tamer with [Kari Kamiya] in its name, place this card on top of your security stack. --- [Security] All of your opponent's Digimon and security Digimon get -5000 DP until the end of your turn.
Revelation of Light BT15-092 U When an effect trashes this card from the security stack, activate this card's [Security] effects. [Main] Search your security stack. You may play 1 yellow level 4 or lower Digimon card among it without paying the cost. Then, shuffle your security stack. If you have a Tamer with [Kari Kamiya] in its name, place this card on top of your security stack. --- [Security] All of your opponent's Digimon and security Digimon get -5000 DP until the end of your turn.
Revelation of Light BT15-092 U When an effect trashes this card from the security stack, activate this card's [Security] effects. [Main] Search your security stack. You may play 1 yellow level 4 or lower Digimon card among it without paying the cost. Then, shuffle your security stack. If you have a Tamer with [Kari Kamiya] in its name, place this card on top of your security stack. --- [Security] All of your opponent's Digimon and security Digimon get -5000 DP until the end of your turn.
光の天啓 BT15-092 U 効果でこのカードがセキュリティから破棄されたとき、このカードの【セキュリティ】効果を発揮する。 【メイン】自分のセキュリティを全て確認する。その中の黄のLv.4以下のデジモンカード1枚をコストを支払わずに登場できる。その後、自分のセキュリティをシャッフルする。名称に「八神ヒカリ」を含む自分のテイマーがいるなら、このカードを自分のセキュリティの上に置く。 --- 【セキュリティ】自分のターン終了まで、相手のデジモンとセキュリティデジモン全てをDP-5000。