“After difficult trials, the four of them arrive to a mysterious environment in the depths of the ruins”

“Regaining their strength through Aussa’s recovery medicine and Eria’s bentos, they try the Grand Spiritual Art once again”

“While their wills are put to the test, and the familiars mustering all of their power, will they be able to complete the ‘Grand Spiritual Art – Ichirin’?…”

The episode premieres on March 20th, at 7 PM JST.
(once again, the date listed in English differs, listing it as March 23rd, 7PM JST)

Source.

Finally, a comment has been posted by Aussa’s voice actress, Mikako Komatsu:
“It is an honor to once again have the opportunity to be involved with the world of Yu-Gi-Oh!.
Aussa the Earth Charmer is diligent, boyish and timid.
Sometimes she starts arguing with Hiita (lol), but I wish you keep supporting all four of them and their friendship!
I am also the voice of the familiar, Archfiend Marmot of Nefariousness! Pi!”

Source.

As a note, Mikako Komatsu previously voiced Kotori Mizuki in Yu-Gi-Oh! ZEXAL.