Q1: What does this card's On Play When Digivolving effect do, exactly?
If DNA Digivolving, you choose 1 of your opponent's Digimon and return all of your opponent's Digimon with the same level to the bottom of the deck. For example, if you use this effect to choose a level 3 Digimon, you return all of your opponent's level 3 Digimon to the bottom of the deck. Then, you delete 1 of your opponent's Digimon.
Q2: If this card didn’t DNA digivolve, can its On Play / When Digivolving effect still delete one of the opponent’s Digimon?
Yes, you may still delete one of the opponent's Digimon.
Lv.7 Omnimon ACE BT17-078 SR Mega | Vaccine | Holy Warrior/Royal Knight [DNA Digivolution] Lv.6 w/[Greymon] in name+Lv.6 w/[Garurumon] in name: Cost 0 [Hand] [Counter] <Blast DNA Digivolve ([WarGreymon] + [MetalGarurumon])> (1 of your specified Digimon and 1 specified card in the hand may DNA digivolve into this card.) <Raid> <Blocker> [On Play] [When Digivolving] If DNA digivolving, choose 1 of your opponent's Digimon, and return it and all of their Digimon with the same level as it to the bottom of the deck. Then, delete 1 of their Digimon. --- Inherited: <Overflow (-5)> (As this card moves from the battle area or under a card to another area, lose 5 memory.)
Lv.7 Omnimon ACE BT17-078 SR Mega | Vaccine | Holy Warrior/Royal Knight [DNA Digivolution] Lv.6 w/[Greymon] in name+Lv.6 w/[Garurumon] in name: Cost 0 [Hand] [Counter] <Blast DNA Digivolve ([WarGreymon] + [MetalGarurumon])> (1 of your specified Digimon and 1 specified card in the hand may DNA digivolve into this card.) <Raid> <Blocker> [On Play] [When Digivolving] If DNA digivolving, choose 1 of your opponent's Digimon, and return it and all of their Digimon with the same level as it to the bottom of the deck. Then, delete 1 of their Digimon. --- Inherited: <Overflow (-5)> (As this card moves from the battle area or under a card to another area, lose 5 memory.)
Lv.7 Omnimon ACE BT17-078 SR Mega | Vaccine | Holy Warrior/Royal Knight {{DNADigivolveFromArchetype|0|6|Greymon|6|Garurumon}} [Hand] [Counter] <Blast DNA Digivolve ([WarGreymon] + [MetalGarurumon])>. <Raid> <Blocker> [On Play] [When Digivolving] If DNA Digivolving, choose 1 opponent's Digimon and return the chosen Digimon and all of your opponent's Digimon with the same level to the bottom of the deck. Then, delete 1 of your opponent's Digimon. --- Inherited: <Overflow (-5)> (As this card moves from the battle area or under a card to another area, lose 5 memory.)
Lv.7 オメガモンACE BT17-078 SR 究極体 | ワクチン種 | 聖騎士型/ロイヤルナイツ 〔ジョグレス〕名称に「グレイモン」を含むLv.6+名称に「ガルルモン」を含むLv.6:コスト0 [手札]【カウンター】≪ブラストジョグレス《「ウォーグレイモン」+「メタルガルルモン」》≫(指定の自分のデジモン1体と手札の指定のカード1枚で、このカードにジョグレス進化できる) ≪突進≫≪ブロッカー≫ 【登場時】【進化時】ジョグレス進化していたなら、相手のデジモン1体を選び、選んだデジモンと同じLv.の相手のデジモン全てをデッキの下に戻す。その後、相手のデジモン1体を消滅させる。 --- Inherited: ≪オーバーフロー《-5》≫(バトルエリアかカードの下から、それ以外の場所に送られる場合、メモリー-5)