GUNDAM VERSUS

A navigator is a character that appears commentating on your side of the screen while you are fighting against your opponents in-game, much like those seen in Mobile Suit Gundam Extreme vs. Maxi Boost and Maxi Boost ON in the arcades. The navigator's comments in-game vary depending on many situations, such as how you're doing in a battle, whether an enemy approaches you, and when the match is over. Please refer to these screenshots below for the situations as to when navigators appear in-game.
 

Top Screenshot: An example of a navigator commenting on the current situation or your performance while you are fighting in a match.

Bottom Screenshot: An example of a navigator commenting when you win or lose a match.

You can unlock navigators for purchase once you have levelled up a mobile suit that has one in their development tree (such as Gundam, or Throne Drei, for example) to level 15, once they are unlocked, you can purchase them for at least 50,000 GP, which means that you will need to spend at least 250,000 GP in order to unlock this and the trophies above it. Keep in mind that while the description does not mention it, any navigators that you can obtain from DLC mobile suits (e.g. Aida Surugan from G-Self (Perfect Pack)) will not count towards these trophies.