Mankato (KMKO)-Formal charges were filed yesterday against a man accused of threatening someone with a knife and fighting with police in Mankato.  26-year-old Nathan Vickers was arrested after an altercation in a bar Thursday night.  Once outside, Vickers threatened the man with a knife.  After being arrested, Vickers fought with officers.  The struggle continued in the Blue Earth County Jail, with officers using a taser to subdue the man.  Vickers appeared before Judge Bradley Walker yesterday.  He was charged with six felonies, including assault, terroristic threats and possession of a controlled substance.  He remains jailed pending further proceedings.