Rulings
Q1: When I use this card's On Play When Digivolving effect to place a card on top of my security stack, can I place an Option card with an original cost of 6 or more that has its cost reduced upon use?
No, you can't. Option cards that reduce the cost upon use don't change the card's original cost, therefore you can't use this card's effect to place such a card on top of your security stack.
Q2: When I use this card's On Play When Digivolving effect to place an Option card on top of my security stack, can I place an Option card that had its cost reduced to 5 or less by a "reduce the cost of this card in the hand by 1" effect on a card such as BT2-099 Glorious Burst or BT8-097 Crimson Blaze?
Yes, you can. If the cost of an Option card consistently changes when it's in the hand and becomes 5 or less due to that card's effect, you can use this card's effect to place it on top of your security stack.
Data Sources
Lv.6 Sakuyamon: Maid Mode ACE LM-023 P Mega | Data | Shaman [Digivolve] [Sakuyamon]: Cost 1 [Hand] [Counter] <Blast Digivolve> (Your Digimon may digivolve into this card without paying the cost.) [On Play] [When Digivolving] You may place 1 yellow Tamer card or 1 single-color use cost 5 or lower Option card from your hand as your top security card. [All Turns] [Once Per Turn] When Option cards are used or security stacks are added to, 1 of your opponent's Digimon gets -6000 DP for the turn. --- Inherited: <Overflow (-4)> (As this card moves from the field or under a card to an area other than those, lose 4 memory.)
Lv.6 Sakuyamon: Maid Mode ACE LM-023 P Mega | Data | Shaman [Digivolve] [Sakuyamon]: Cost 1 [Hand] [Counter] <Blast Digivolve> (One of your Digimon may digivolve into this card without paying the cost.) [On Play] [When Digivolving] You may place 1 yellow Tamer card or single-color Option card with a cost of 5 or less from your hand on top of your security stack. [All Turns] [Once Per Turn] When you use an Option card or when a card is added to your security stack, 1 of your opponent's Digimon gets -6000 DP for the turn. --- Inherited: <Overflow (-4)> (When this card would move from the battle area or under a card to another area, lose 4 memory.)
Lv.6 Sakuyamon: Maid Mode ACE LM-023 P
Mega | Data | Shaman
[Digivolve] [Sakuyamon]: Cost 1
[Hand] [Counter] <Blast Digivolve> (One of your Digimon may digivolve into this card without paying the cost.)
[On Play] [When Digivolving] You may place 1 {{Colour|yellow}} Tamer card or 1 single-color Option card with a cost of 5 or less from your hand on top of your security stack.
[All Turns] [Once Per Turn] When an Option card is used, or when a card is added to a security stack, 1 of your opponent's Digimon gets -6000 DP for the turn.
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Inherited: <Overflow (-4)> (As this card moves from the battle area or under a card to another area, lose 4 memory.)
Lv.6 サクヤモン：巫女モードACE LM-023 P 究極体 | データ種 | 神人型 「サクヤモン」:コスト1 ［手札］【カウンター】≪ブラスト進化≫（自分のデジモンをこのカードにコストを支払わずに進化できる） 【登場時】【進化時】自分の手札から、黄のテイマーカードか1色の使用コスト5以下のオプションカード1枚を自分のセキュリティの上に置ける。 【お互いのターン】[ターンに1回]オプションカードを使用したときか、セキュリティが増えたとき、ターン終了まで、相手のデジモン1体をDP-6000。 --- Inherited: （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-4）