Ultra Galaxy Legend Gaiden:Ultraman Zero vs. Darclop Zero! ~ CSToys Blog, We're With Heroes

To promoteUltraman Zero The Movie: Super Deciding Fight! The Belial Galactic Empire, two special DVDs will be released to lead up to the storyline of the movie titled Ultra Galaxy Legend Gaiden: Ultraman Zero vs. Darkrops Zero.
Shota Minami, Hiroyuki Konishi, and Mamoru Miyano reprise their roles from Ultra Galaxy Mega Monster Battle, Never Ending Odyssey, and Mega Monster Battle: Ultra Galaxy Legend The Movie in these DVDs.The Gaiden will also feature Darkrops Zero (ダークロプスゼロ) who can wear an armor similar to the Techtor Gear Zero called Techtor Gear Black (テクターギアブラック) along with the Gomora doppelganger, the Mecha Robot Monster Mecha Gomora. Also appearing are the mass produced robot Imitation Ultra Brotherscreated by the Alien Salome Herodia, which includes Imit Ultra Seven (SR), as the leader, Imit Zoffy (SR), Imit Ultraman (SR), Imit Ultraman Jack (SR), Imit Ultraman Ace (SR).

So, the spreading rumor of dark version of ultras were actually imitation ultras for the Ultra Galaxy Legend gaiden movie. Below here is the image used on the rumored news.

Image source from Jefusion

Like the previous Ultraman Mebius Gaiden movie, this 1 will be also serparated into 2 stages of DVD.
Both released on different date.
Stages:

Cosmic Collision (衝突する宇宙, Shōtotsu suru Uchū) - November 26, 2010
Zero's Suicide Zone (ゼロの決死圏, Zero no Kesshiken) - December 22, 2010

Here are the synopsis I've gotten from CDjapan online store.

Stage I features the episode "Shototsu Suru Uchu." Hyuga and Rei drift down to the planet Cheney and encounter the mysterious giants which are practically the clones of Ultraman and UltraSeven. Suddenly mysterious mechanic monster appears and Ultraman Zero hurries to rescue. There he sees . . .

Stage II features the episode "Zero no Kesshiken." Hyuga sneaks into mysterious alien base to rescue Rei. On the other hand, Ultraman Zero wages a fierce battle in the unknown space. What is going to happen to them? And a great mystery of the planet Cheney will be revealed. . .

And a PV is now up on Tsuburaya's Official Youtube channel. So, check it out and enjoy. ^_^