Rulings
Q1: This card has 3 different cards in its App Fusion requirements. What combinations are possible for App Fusion?
App Fusion is possible with the following combinations. <ul><li>Gatchmon with Navimon link card<li>Gatchmon with Tweetmon link card<li>Navimon with Gatchmon link card<li>Navimon with Tweetmon link card<li>Tweetmon with Gatchmon link card<li>Tweetmon with Navimon link card</ul>
Q2: I link BT21-018 DoGatchmon with this card and use its effect to attack. Can I then use the effect on the linked BT21-018 DoGatchmon to attack?
No, you can't use the effect on the linked BT21-018 DoGatchmon to attack. A new attack declaration can't be made during an attack. In this case, this card's Your Turn effect and BT21-018 DoGatchmon's When Linking effect trigger simultaneously, and this card's Your Turn effect is used to attack. BT21-018 DoGatchmon's When Linking effect can be activated before the counter timing, but because you can't declare another attack during an attack, you won't be able to attack using the linked BT21-018 DoGatchmon's When Linking effect, even if you activate it.
Data Sources
Lv.4 DoGatchmon BT21-018 R Sup./Appmon | Social | Super Search/Hero [App Fusion] [Gatchmon] & [Navimon] & [Tweetmon]: Cost 0 (If 2 such cards are linked together, stack the link card on top and digivolve.) <Rush> <Raid> [Your Turn] [Once Per Turn] When this Digimon gets linked, it may attack. --- Link: +3000 DP <Link> [Appmon] trait: Cost 2 (Plug this card from the hand or battle area sideways into the specified Digimon in the battle area.) Link: [When Linking] This Digimon may attack.
Lv.4 DoGatchmon BT21-018 R Sup./Appmon | Social | Super Search/Hero [App Fusion] [Gatchmon] & [Navimon] & [Tweetmon]: Cost 0 (If 2 such cards are linked together, stack the link card on top and digivolve.) <Rush> <Raid> [Your Turn] [Once Per Turn] When this Digimon gets linked, it may attack. --- <Link> [Appmon] trait: Cost 2 (Plug this card from the hand or battle area sideways into the specified Digimon in the battle area.) Link: [When Linking] This Digimon may attack. Link: [Linked Together] +3000 DP
Lv.4 DoGatchmon BT21-018 R
Sup./Appmon | Social | Super Search/Hero
{{AppFusion|0|Gatchmon|Navimon|Tweetmon}}
<Rush>
<Raid>
[Your Turn] [Once Per Turn] When this Digimon gets linked, it may attack.
---
<Link> [Appmon] trait: Cost 2
Link: +3000DP
Link: [When Linking] This Digimon may attack.Lv.4 ドガッチモン BT21-018 R 超/アプモン | ソーシャル | 超検索/ヒーロー ≪速攻≫≪突進≫ 【自分のターン】[ターンに1回]このデジモンがリンクしたとき、このデジモンでアタックできる。 --- 〈リンク〉特徴「アプモン」:コスト2（手札/バトルエリアから、このカードをバトルエリアの指定のデジモンに横向きで差し込む） リンク: +DP+3000DP リンク: 【リンク時】このデジモンでアタックできる。