Joining the likes of Dialga, Lunala, and Zekrom, Pokémon Sword and Shield’s legendary title creatures are Zacian and Zamazenta.
As predicted, both are wolf-like Pokémon that come with a shield and sword in how their appearance that influences their moves and attacks. It also looks like the two will either be separate forms of the same Pokémon or a branch evolution like with what Lunala and Solgaleo were in Pokémon Sun and Moon.
The sword in Zacian holds in its mouth is said to have the ability to cut through anything and, much like Suicune, its movements are graceful, practiced, and will captivate opponents. Meanwhile, Zamazenta can turn back any attack with its shield-like form and will overwhelm any enemy that challenges it.
They were initially shown battling one another in a dense forest, which is probably unrelated to where the player will find them in-game but based on the detail of the trailer, it also could be a vital clue for when the games release to the public. GameFreak stated that both Pokémon are shrouded in mystery even to the inhabitants of the Galar region, so these small details might add up later.
Both Pokémon are likely going to have a tremendous impact on the story, likely with a focus on the late game as is typical in most games. This will also likely include some tie-in with whatever the unannounced evil team will be trying to accomplish throughout Sword and Shield’s story.
It is currently unknown if Zacian and Zamazenta will be available in both Sword and Shield or if they will are exclusive to their respective games. It is possible players may have the chance to catch whichever Pokémon is on the cover of their game and then can later capture the opposite legendary during the post-game.