

Q1: If an opponent's Digimon is attacking and another effect digivolves one of my Digimon into this card, does that meet the "if during an attack" condition in this card's On Play When Digivolving effect?
Yes, it does.
Lv.5 Hisyaryumon BT20-015 R Ultimate | Vaccine | Beast Dragon/X Antibody/Chronicle [On Play] [When Digivolving] You may play 1 [Dorumon] or [Ryudamon] from your hand to your empty breeding area without paying the cost. Then, if during an attack, until the end of your opponent's turn, 1 of your Digimon gains <Security A.+1> and gets +5000 DP. --- [Your Turn] This Digimon doesn't activate [Security] effects on Option cards it checks.
Lv.5 Hisyaryumon BT20-015 R Ultimate | Vaccine | Beast Dragon/X Antibody/Chronicle [Digivolve] [Ginryumon] or Lv.4 w/[Chronicle] trait: Cost 3 [On Play] [When Digivolving] You may play 1 [Dorumon] or [Ryudamon] from your hand to your empty breeding area without paying the cost. Then, if during an attack, until the end of your opponent's turn, 1 of your Digimon gains <Security A.+1> and gets +5000 DP. --- [Your Turn] This Digimon doesn't activate [Security] effects on Option cards it checks.
Lv.5 Hisyaryumon BT20-015 R ultimate | Vaccine | Beast Dragon/X Antibody/Chronicle [Digivolve] [Ginryumon] or Lv.4 w/[Chronicle] trait: Cost 3 [On Play] [When Digivolving] You may play 1 [Dorumon] or [Ryudamon] from your hand to your empty breeding area without paying the cost. Then, if during an attack, until the end of your opponent's turn, 1 of your Digimon gains <Security A. +1> and gets +5000 DP. --- [Your Turn] This Digimon doesn't activate [Security] effects on Option cards it checks.
Lv.5 ヒシャリュウモン BT20-015 R 完全体 | ワクチン種 | 獣竜型/X抗体/クロニクル 【登場時】【進化時】自分の手札から、「ドルモン」/「リュウダモン」1枚を空いている自分の育成エリアにコストを支払わずに登場できる。その後、アタック中なら、相手のターン終了まで、自分のデジモン1体は≪Sアタック+1≫を得て、DP+5000。 --- 【自分のターン】このデジモンがチェックしたオプションカードの【セキュリティ】効果は発揮しない。