ShineGreymon

Q:Can I use this card's [When Digivolving] effect to choose opponent's Digimon and reduce their DP for each of my yellow or red Tamers?

A:No, you can't. You choose 1 of your opponent's Digimon, then that Digimon and all security Digimon get -3000 DP for each of your yellow or red Tamers.

Q:If a [Marcus Damon] Tamer isn't treated as a Digimon and doesn't have DP, does this card's [Your Turn] effect treat it as having 3000 DP and give it ?

A:It won't be treated as having DP, but it will gain . If a card doesn't have DP, it won't be treated as having DP, and DP can't be added to it. DP can be added if a [Marcus Damon] Tamer is treated as a Digimon and has DP.