Board Thread:General Discussion/@comment-67.70.92.41-20151228204640/@comment-4010415-20160218044304

I think an interesting thing to note is that Mercury's father was a professional assassin who taught Merc how to be an assassin (Cinder says "He taught you well" and Merc replies "Guess so", confirming that, yeah, Marcus taught Merc).

So... Teams RWBY and JNPR have been taking classes that teach them how to combat Grimm, with a sparring class taught by Glynda on the side.

Mercury grew up with a man who taught him how to combat people. Not just how to fight people, but also how to kill them.

So, everything Merc knows revolves around his training to be an assassin, while Teams RWBY and JNPR have been taking classes where their teachers are telling them "Kill Grimm and have friendly sparring matches with classmates!"