It seems Nintendo forgot to cast Holy Protection before updating their servers, as a handful of Dragon Quest spirits have been found in Nintendo’s Spirits Database. These are images that are used whenever a new Spirit Board event is announced, and it seems some spirits for Dragon Quest have been archived.
These were found by messing around with Nintendo’s URLs to find various images of spirits. Keep in mind that we don't know exactly how long many of these images have been up for, or if these are all the Dragon Quest spirits we will be getting. Regardless, their presence shows that the Hero is just about ready to launch.
Before going into more detail, I feel I should throw out the obvious Spoiler Warning! Not only for the spirits that will be coming with the Hero, but for spoilers of the series itself, particularly for Dragon Quest XI, as it seems Sakurai is still not one to shy away from minor character-related spoilers in Smash Bros.
The list of spirits confirmed so far is as follows: (EDIT: The Spirit links have since been taken down, no doubt due to them becoming wide spread, so none of the links below work.)
-Dragon Quest XI Party Members
The Spirit for the party of Dragon Quest XI apparently has a particularly notable character in it who might not be common knowledge, so if you're still hoping on remaining completely spoiler-free for Dragon Quest XI, you might want to pass on using the DLC Spirit Board before getting far into the game, or before the Switch port.
Interestingly, the Spirits for the monsters use Akira Toriyama's original drawings of them rather than the updated renders seen in later games, which is a nice touch.
Author’s Note: It seems the Hero is coming very soon, between this and several other tidbits of information sprinkled around recently. What do you think of this? Is the Hero coming this week? Or maybe EVO? Are there any particular spirits you feel are absent? The lack of spirits from 8 is a bit disappointing for me, but it's great that we're even getting any after Final Fantasy got shafted. Let us know what you think in the comments!