Unique Monsters are pretty much considered mini-bosses in Xenoblade Chronicles, and the latest gameplay footage for Xenoblade Chronicles 3D shows Shulk and the others team up to take one down.
What made Unique Monsters important in the original Xenoblade Chronicles is how they drop Affinity Coins, used to set up skill links between characters. While they can be obtained by leveling up characters, getting them from the 157 Unique Monsters surely came in handy.
Additionally, director Tetsuya Takahashi and other developers from Monolith Soft are expected to appear in an upcoming NicoNico Livestream on the 26th, for Xenoblade Chronicles 3D, which will be aimed for those that are new to the series.
Xenoblade Chronicles 3D is slated for release on April 10 in North America and April 2nd in Europe for Nintendo 3DS.