Guild buffs are a thing you can get in your guild home (also Patreon exclusive atm) once you unlock the silver badge. Every 10 levels, a character gets a set of three possible permanent buffs you can choose from. Most of these buffs are to boost your weapon damage or give you new skills, but since people were really struggling with the amount of enemy encounters in the Water Dungeon, he also made one that makes dungeon runs easier.