Q1: If this card's On Play and When Digivolving effects cause a Digimon in the Breeding Area to digivolve, does the Digimon's When Digivolving effect trigger?
No, it does not trigger.
Q2: If the Security effect, the "when security is checked" effect, and the "when security is reduced" effect are triggered simultaneously, in which order do they activate?
Security] effects are activated first. Security] effects, if checked, will be activated immediately without pending activation. Other triggered effects are activated from the turn player's side.
Lv.6 Ouryumon BT20-018 R Mega | Vaccine | Beast Dragon/X Antibody/Chronicle <Piercing> (When this Digimon attacks and deletes an opponent's Digimon, it performs any security checks it normally would.) [On Play] [When Digivolving] <De-Digivolve 2> 1 of your opponent's Digimon. Then, if during an attack, 1 of your Digimon in the breeding area may digivolve into a level 6 or lower [Chronicle] trait Digimon card in the hand or trash without paying the cost. [All Turns] [Once per Turn] When security stacks are removed from, delete 1 of your opponent's Digimon with the lowest DP. --- Inherited: [When Attacking] [Once Per Turn] If this Digimon is [Alphamon: Ouryuken], trash your opponent's top security card.
Lv.6 Ouryumon BT20-018 R Mega | Vaccine | Beast Dragon/X Antibody/Chronicle <Piercing> (When this Digimon attacks and deletes an opponent's Digimon, it performs any security checks it normally would.) [On Play] [When Digivolving] <De-Digivolve 2> 1 of your opponent's Digimon. Then, if during an attack, 1 of your Digimon in the breeding area may digivolve into a level 6 or lower [Chronicle] trait Digimon card in the hand or trash without paying the cost. [All Turns] [Once Per Turn] When security stacks are removed from, delete 1 of your opponent's Digimon with the lowest DP. --- Inherited: [When Attacking] [Once Per Turn] If this Digimon is [Alphamon: Ouryuken], trash your opponent's top security card.
Lv.6 オウリュウモン BT20-018 R 究極体 | ワクチン種 | 獣竜型/X抗体/クロニクル ≪貫通≫ 【登場時】【進化時】相手のデジモン1体を≪退化2≫。その後、アタック中なら、育成エリアの自分のデジモン1体を手札/トラッシュの特徴に「クロニクル」を持つLv.6以下のデジモンカードにコストを支払わずに進化できる。 【お互いのターン】[ターンに1回]セキュリティが減ったとき、最もDPの低い相手のデジモン1体を消滅させる。 --- Inherited: 【アタック時】[ターンに1回]このデジモンが「アルファモン:王竜剣」なら、相手のセキュリティを上から1枚破棄する。