In this challenge, you are fighting both Justin Goncalves and Mike Sleva, the creators of the game, by yourself. Beating this challenge requires you to try to keep your distance from them as they are tough to kill close-up. For Justin, aim at the head and stop firing when he activates Blur. For Mike, aim for his back when he's not looking at you. Warning: Mike has Iron Will, so if you're using a high damage, low fire rate weapon, aim a shot to take out iron will before switching back to main weapon. Both of them are level 60. Recommended to have a high level assassin with an AWP. For commando a commando is very useful on Mike with 2 hits.
Justin is a Commando with a Minigun and Mike is a Tank with a Siegius and SPAS 12.