Looking for a young adult science fiction book I read in the 90s. I think the focus was on a Earth teen male, that somehow joins a space resistance group.
It’s not The Tripod series or Under Alien Stars by Pamela F Service.
I remember the resistance group introduced the teen to certain weapons that were used cautiously, as the use would identify them as part of this group. Their weapons included a type of exploding stun ball and a ring or maybe a watch that would temporarily make the wearer appear as a 8 foot monster, both were used in a fast paced chaotic scene that may have included climbing through air vents.