User blog comment:Zoroark555/Who Is Your True Buddy?/@comment-3974145-20160329212057

It should be noted that for some cards they depict an entire species and not just one monster while others depict a single monster that is one of a kind.

For example, Drum Bunker Dragon and Jackknife Dragon have been shown in the anime to just be a single species. The Drum we know in the anime has an actual name and other Drum Bunker Dragons exist with different colorations. The same can be said for some other cards.

While certain cards are one of a kind like say the Dragon Knights, every one of them is a unique monster that has no other in Dragon World. There are quite a few cards like that in the anime, so say El Quixote is Noboru's buddy and such no one else can Buddy him unless those two part ways.

Now in some cases I've seen there have been one of a kind monsters but they belong to a certain species. Example, Nanomachine Ninja Tsukikage and Byakuya. They belong to a species known as the Nanomachine Ninja but it would seem that each Nanomachine Ninja is different with a different name look and personality. So though Tsukikage and Byakuya are out I believe we'll get more Nanomachine Ninja eventually.

This has been a nice long prompt teaching everyone more about Buddyfight, any questions? ^-^