A Public Event where you have to hunt down a Rogue Guardian NPC would be cool. They'd have a random class and subclass, have access to all three of their grenade types, and a rapidly recharging Super. Weapons would be determined by class: Titans have Auto+Shotgun, Hunters have Scout Rifle+Sniper, and Warlocks Pulse+Fusion. For durability, they'd be much tougher than any player Guardian, but not quite as tough as the other "Eliminate the Target" events. They'd be unmarked on the HUD, meaning you'd have to actually hunt them down. Because of their toughness and the fact you have to actively find them, the event would be ten minutes long instead of five.