Honor

Spawning in one variant of Desolate Forest, the artifact can be seen on the far left on the bottom level. You will need either: two Rusty Jetpacks, a Photon Jetpack, or to play as the Miner in order to get to it or the whirlwind ability for the mercenary while jumping (effectively a double jump), due to the jumps involved at the entrance.

The Miner's fourth V skill To The Stars will give him additional jump height if used correctly. The artifact itself is visible from the very bottom, it looks like a purple cube and does not sit on top of the artifact gate, like the others. Picking it up will unlock the Honor artifact, which will make all enemies spawn as elites. By doing that, the spawn rate of mobs altogether is drastically lowered. By activating the artifact, it will only stop any normal mobs from spawning and will keep the same spawn rate for elites. In addition to that, all bosses will spawn as elites.