Reading through the trademark application tells us little about what Soulcalibur: Unbreakable Soul might be. Its approved uses suggest that this will be a new video game (or potentially an online service) but beyond that details are scarce. We've reached out to Namco Bandai for more information, but the company was unwilling to comment.
If Soulcalibur: Unbreakable Souls is indeed a new Soulcalibur game, it would mark the third such project currently in progress at Namco Bandai. Not only is the publisher developing a high-definition remake of fan-favorite Soul Calibur II, but it's also working on the free-to-play fighter Soulcalibur Lost Swords.