

Q1: Can I use this card's When Digivolving effect to give "Start of Your Main Phase This Digimon attacks" to a Digimon that isn't affected by effects?
You can give that effect to such Digimon, but if the Digimon isn't affected by effects upon the trigger timing, the gained effect won't trigger.
Lv.5 WereGarurumon BT23-056 C Ultimate | Virus | Beastkin/CS <Blocker> [On Play] [When Digivolving] If you have a Tamer with the [CS] trait, give 1 of your opponent's Digimon "[Start of Your Main Phase] This Digimon attacks." until their turn ends. --- [All Turns] [Once Per Turn] When attack targets change, <De-Digivolve 1> 1 of your opponent's Digimon.
Lv.5 WereGarurumon BT23-056 C Ultimate | Virus | Beastkin/CS [Digivolve] Lv.4 w/[CS] trait: Cost 3 <Blocker> [On Play] [When Digivolving] If you have a Tamer with the [CS] trait, give 1 of your opponent's Digimon "[Start of Your Main Phase] This Digimon attacks." until their turn ends. --- [All Turns] [Once Per Turn] When attack targets change, <De-Digivolve 1> 1 of your opponent's Digimon.
Lv.5 WereGarurumon BT23-056 C ultimate | Virus | Beastkin/CS [Digivolve] Lv.4 w/[CS] trait: Cost 3 <Blocker> [On Play] [When Digivolving] If you have a Tamer with the [CS] trait, give 1 of your opponent's Digimon "[Start of Your Main Phase] This Digimon attacks." until their turn ends. --- [All Turns] [Once Per Turn] When attack targets change, <De-Digivolve 1> 1 of your opponent's Digimon.
Lv.5 ワーガルルモン BT23-056 C 完全体 | ウィルス種 | 獣人型/CS ≪ブロッカー≫ 【登場時】【進化時】特徴に「CS」を持つ自分のテイマーがいるなら、相手のターン終了まで、相手のデジモン1体に「【自分のメインフェイズ開始時】このデジモンでアタックする。」の効果を与える。 --- 【お互いのターン】[ターンに1回]アタックの対象が変更されたとき、相手のデジモン1体を≪退化1≫。