There's a pretty interesting lineup for this!
Obviously the headline is pre-Rayblood Belial. That doesn't necessarily mean he'll be a good guy. He was exiled from the land of light when he was in this form. Alternatively, it could be post-Geed, where he was purified by his son as he died.
The other two "poster boys" are Zero (of course, it's his 10th anniversary) and Ribut, who made his screen debut in the previous Ultra Galaxy Fight. Behind them is lurking a new (I think) villain called Absolute Tartarus.
Also appearing in the trailer are:
The Ultra Brothers (Ultraman, Zoffy, Ultra Seven, Jack, Ace, Taro).
Ultraman 80 - it's his 40th anniversary so it would be cool for him to get something to do.
Yullian - now with a fancy cape because she's a princess rather than an Ultra warrior. Again, it would be nice for her to get something to do. I think since 80 ended she's only had two quick cameos in the Zero movies.
With them is a real obscure face - Sora. This will be her screen debut, as she's only previously appeared in a stage show. She is voiced by Megumi Han, who previously voiced Pega in Ultraman Geed, but may be better known among toku fans for playing Kyuemon/Midoninjer in Shuriken Sentai Ninninger.
Next up are two more Ultras celebrating their (20th) anniversary - Ultraman Neos and Ultraseven 21.
Then there are the two Western boys, Great and Powered. They are kinda having an anniversary, as it's 25 years since they were both first shown on Japanese TV (although Great had been shown on American TV three years earlier, and Powered had previously been available on video in Japan).
Mebius is also back (sadly still with replacement voice actor).
From last year's main series, the Tri Squad - Taiga, Titas, and Fuma.
Ultraman Hikari (originally from Mebius) is back, and shown once again donning the armor to become Hunter Knight Tsurugi.
Taiga's villain Tregear is fighting Taro again.
Ultrawoman Grigio is back, this time without her elder brothers Rosso and Blu.
Ultraman Max, who is also celebrating his 15th anniversary.
And of course, the new boy, Ultraman Z.
Last year's Ultra Galaxy Fight was a prequel to Taiga's series, so it's possible this season will be a prequel to Z.
Also, it looks like they're bringing back most of the major variations of alien Zetton, which is good news for me as he's one of my personal favorites.