Completely minor but, I've noticed on the wiki page for Devilites, the Yesman tab clearly states "Increases defense of Pit Bosses" as one of its abilities. This defense buff to Pit Bosses is for some reason is not actually visible and cannot be identified until you actually test out the difference between damaging a Pit Boss when a Yesman is absent, and when one is present. Other monsters that have moves that buff monsters around them (or in certain cases, themself) are clearly indicated. Whenever the Trojan uses it's buff move (the move that also can inflict the shock status,) you can see a faded sword icon, indicating the enemy can deal more damage currently. This attack buff is also commonly visible in Alpha Wolvers increasing attack power for all the Wolvers around it, again, indicated by the faded sword icon above them.

Easy solution to the problem. Whenever the Yesmen use this ability to a nearby Pit Boss, indicate that it has a defense buff with a faded shield icon over head. This way it keeps consistency with the other stat-changing moves on enemies in the game.