User blog comment:Daniel 1939/About the Supporting Casts/@comment-6697950-20140119084129

A little off topic, but I would like to remind you that the anime is just and adaptation, so Sinon already is a main heroine in the Phantom Bullet arc.

Back on topic, I personally believe that Klein is a decent comedic relief in the series and I'm disappointed that he has so little time to shine. Wasted potential. Unlike the other characters, he doesn't even have a series where he'd be important.

For Agil, he's pretty much the least important secondary character in the series, as he spends most of the day at his cafe and only appears as a minor or background character in other stories. He didn't even get to participate in Caliber, as he was busy. However, he will likely beat Klein in number of appearances with the Progressive series, where Agil was active on the front lines. Too bad no one is bothering to translate Progressive right now. As a character, I can't really say much about him, as he just doesn't appear enough for me to get familiar with him enough.

Silica and Lisbeth are females in the series, thus they get more time to shine than the males and even have a spin off manga to shine in. Other than that, they are also mostly background characters, but I honestly don't care that much about them, as we have plenty of other females in the cast, yet the males aside from Kirito are all pushed to the sidelines.