Headhunter Buffs While NOT Wearing the Belt

Edit - nevermind, I'm told its a map mod.

Do you never look at the map mods while you're running Cortex to have an idea of what buffs the monsters/bosses are getting?

Synthesis areas have special modifiers from the "Map has (2-4) additional Synthesis Global Modifiers" line on the map itself. These modifiers involve synthesised monsters, packs, or chests.

One such modifier is "When a Player Kills a Synthesised Rare Monster, they gain its Modifiers for 20 seconds".