The best way to collect rare materials like Orbs or Sunlight Stone in Demon Piece is by defeating challenging bosses. So, if you are a beginner, here is a list of all boss drops and their Spawn Locations in Demon Piece for you to learn from.

Below I've collected all the bosses in Demon Piece, including their spawn locations, rarities, and the fastest way to defeat them in the game.

Renier is the first boss in Demon Piece for the Pirates. You can find him in the southern part of Windmill Village (Spawn Island). I recommend taking this fight after you have reached level 30 and have at least level 15 mastery with your standard punch.

He is a very mobile boss who keeps running in all directions. So the best strategy is to get behind him when he stops running and hit him in the neck. Also avoid getting in front of him to get hit by his punch. Repeat this loop of getting behind him and dodging punches to take out Renier.