system
Given the following post, respond as if you're commenting on Reddit:
human
[Hellsing/Yu-Gi-Oh] Millennium gets ahold of the Millennium items. How bad is it?

Additionally, would they be required to play children's card games in order to utilize the power, and if so, what sort of tactical changes must they make in order to fully utilize this? Does it not work if Hellsing refuses to play children's card games? What sort of advantage at them does being a vampire give you? Would the world be any more protected from Millennium's attack on the world with Yu-Gi-Oh characters in it?
gpt
Well, with no special connection to the Shadows or Ancient Egypt, it's not *that* bad. Granted, access to all seven *would* allow them to summon Zorc if they wanted. 

To use them, and their magical powers, they have to win them from their previous owners, or be willingly given them by the same. Usually, the (modern) method of contest is a card game. But it can be any contest. 

Once activated, Millennium certainly becomes stronger. They can see the future, influence chance, remove souls, control minds, all kinds of fun stuff. But, if they are ever challenged to a game, and defeated, those powers are lost. 

Vampirism grants all kinds of advantaged in this regard, however. You can challenge people to a game of "how far can you put this sword into your chest" and win almost every time!


However, Millennium's problem isn't something the Millennium Items can solve. Alucard will still kill everyone without regard for their magical powers, as long as they don't summon Zorc or have access to the three Egyptian God Cards. 


A world with Yu-Gi-Oh! characters in it wouldn't really be any better protected from Millennium, because they attacked swiftly and ruthlessly, and only a few people have the power to summon real, actual monsters. Unless they launched their attack on a city with one of these people in it, the result shouldn't be different. 


If they *did* attack a city Yugi happened to be at, he could technically strike their blimps from the sky with godlike monsters and challenge the Major to a game of some sort - if he still had the Puzzle. Otherwise, there's not a lot anyone could do.