12 official rulings from Bandai, last ruled Nov 1, 2024. Straight answers to how this card actually resolves.

Can the digivolution card's inherited effect cause the opponent's "Sukamon" to be deleted and not itself?
Yes, it is possible.
Ruled Sep 22, 2022
If this card's <On Play> <When Digivolving> effect is activated on an my opponent's [ST12-13]/[Sistermon Ciel], [BT6-084]/[Sistermon Ciel] or [BT7-083]/[Sistermon Ciel (Awakened)], what happens to that Digimon?
The name of the cards [ST12-13]/[Sistermon Ciel] and [BT6-084]/[Sistermon Ciel] is also treated as [Sistermon Noir], and the name of the card [BT7-083]/[Sistermon Ciel (Awakened)] is also treated as [Sistermon Noir (Awakened)], but this is a game rule and not an effect, so if this card's <On Play> <When Digivolving> effect is activated in one of those cards, its name will be changed to [Sukamon] and its name will no longer be treated as [Sistermon Noir] or [Sistermon Noir (Awakened)].
Ruled Mar 28, 2024
Can this card's inherited effect delete an opponent's [Sukamon] to prevent itself from being deleted?
Yes, you can.
Ruled Mar 28, 2024
If this card's <On Play><When Digivolving> effect activates on an opponent's Digimon with a "The name of this card/Digimon is also treated as [XX]" or "This Digimon is also treated as [another color]" effect, what happens to my opponent's Digimon?
The Digimon will be changed to a white Digimon with an original name of [Sukamon], but it does not lose the "also treated as" effect, so it is also treated as the name or color from that effect as well as a white [Sukamon].
Ruled Mar 28, 2024
There are "Sukamon" A and "Sukamon" B in the Battle Area, both of which have this card as their digivolution card. When "Sukamon" A was about to delete, it tried to delete "Scamon" B by the digivolved effect of this card. On the other hand, when "Sukamon" B is deleted, you tried to delete "Scamon" A by the digivolved effect of this card. In this case, can "Sukamon" A activate this card's digivolution effect again?
No, it cannot be activated. Until the first occurrence of the first process is resolved, all "interrupting and activating effects" can be activated only once each. In this situation, until the first "Sukamon" A deletion is resolved, each "When" effect can only be activated once, so "Sukamon" A that has already been activated cannot be activated again.
Ruled Jun 21, 2024
If a card whose original name is changed to "Sukamon", white, DP3000 is digivolved or stacked cards are trashed by , what happens to the card's information?
The card also retains its original name "Sukamon", white, DP 3000. The effect given is carried over even if that one digivolved or the stacked cards are trashed.
Ruled Sep 20, 2024
What happens if a card with the original name "Sukamon", white, DP3000 is stacked cards are trashed by , etc. and become tamers or Digitama cards?
The original name "Sukamon" - White - remains changed to DP3000, but the information on the card that it originally did not have cannot be changed. If the card becomes a tamer or a Digitama card and does not originally have DP, it will remain without DP.
Ruled Sep 20, 2024
What happens if a card such as "BT15-035 Geremon", which has card information in , is changed to the original name "Sukamon", white, DP3000 by the effect of this card?
The information of the card you have is also changed by . For example, the original name of "BT15-035 Gelemon" is "Gelemon/Numemon" by , but if the information of the original card is changed by this effect, the original name will be "Sukamon" only.
Ruled Sep 20, 2024
What happens to a card such as "EX1-005 Tyrannomon" that has been given card information by the effect of this card, but is changed to the original name "Sukamon", white, DP3000 by the effect of this card?
The information on the card obtained by the effect remains the same. For example, if the information on the original card EX1-005 Tyrannomon is changed, the original color will be white and the color will be white and green because the effect of EX1-005 Tyrannomon also treats it as green.
Ruled Sep 20, 2024
"Change an opponent's Digimon to its original name "Sukamon", White, DP 3000." What is the effect?
This effect changes the original name of one opponent's Digimon to "Sukamon", its original color to white, and its original DP to 3000.
Ruled Sep 20, 2024
What happens when this card's <On Play><When Digivolving> effect activates for a Digimon with "(Rule) Name: Also treated as [XX]" or "(Rule) Name: Treated as having [XX]"?
It remains as a white Digimon with 3000 DP and an original name of [Sukamon]. The gained effect is carried over even if the Digimon digivolves or one or more of its top cards are trashed.
Ruled Nov 1, 2024
I have [Sukamon] A and [Sukamon] B with this card in their digivolution cards in the battle area. When [Sukamon] A would be deleted, I attempted to delete [Sukamon] B using this card's inherited effect. On the other hand, when [Sukamon] B would be deleted, I attempted to delete [Sukamon] A using this card's inherited effect. At such times, can [Sukamon] A activate this card's inherited effect again?
No, it can't be activated. Until the processing for the 1st activation has resolved, only 1 activation is possible for each immediate-type effect. In your case, until the deletion of the 1st only [Sukamon] A is resolved, only 1 activation is possible for each "when [...] would" effect, therefore the effect that has already activated for [Sukamon] A can't be activated again.
Ruled Nov 1, 2024
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Questions and answers are Bandai's official rulings, collected and translated by the DigimonCardGame Wiki community and reused here under CC BY-SA. Card names and card text are © their respective publishers; Combalo is not affiliated with Bandai.