Boss Spirits

Boss Spirits turns defeated Forsaken into distinct summonable companions while keeping progression tied to Valheim's existing boss trophies and Forsaken Powers.

Defeat a boss, unlock its Forsaken Power at the Sacrificial Stones, select that power, and press the configurable summon key (default: Z). Press the key again to dismiss your spirit or end a transformation.

Completed spirits

Eikthyr — land mount

• Fast, responsive ground travel.
• Sprinting uses mount stamina.
• High jump with no jump-stamina cost.
• Cannot be mounted while overencumbered.
• Dismounts safely in deep water and during other invalid riding states.

The Elder — resource gatherer

• Command a terrain-following work area.
• Harvests valid wood, stone, copper, tin, and progression-appropriate iron targets.
• Moves between nearby targets and remains assigned to its worksite until recalled.
• Works in supported dungeons and multiplayer.

Bonemass — support companion

• Cycles between Passive, Normal, and Aggressive combat behavior.
• Fires a Growth-style tar projectile that slows and poisons enemies.
• Uses a forgiving invisible impact area without increasing the visible projectile size.
• Returns to the player's combat radius instead of behaving like a stationary turret.
• Can target hostile players only when both players have PvP enabled.

Moder — flying mount

• Walks and runs on land.
• Press and hold Space to ascend.
• Press and hold Left Control to descend.
• Flight consumes stamina and has controlled out-of-stamina descent.
• Uses safe ground and airborne dismount behavior.

Yagluth — combat transformation

• Replaces the player with a controllable Yagluth form.
• Primary attack uses Yagluth's aimed fire breath.
• Secondary attack releases Yagluth's flame nova.
• Uses its own persistent health and stamina, which recover outside the form.
• Provides expanded Mistlands vision while transformed.
• Blocks mortal inventory, equipment, hotbar, and hammer use during possession.
• Cannot damage its owner or player-built structures.
• Can damage another player or transformed Yagluth only when both players enable PvP.

Shared behavior

• One active spirit per player.
• Each player's summon is independently owned and networked.
• Only the summoner can ride their mount.
• Summons follow, navigate, turn smoothly, and teleport back when too far away.
• Lifecycle handling covers death, logout, ships, portals, and invalid summon states.
• Configurable summon key through the BepInEx configuration file or an installed configuration manager.
• Designed to coexist with Passive Powers, WardIsLove, and other commonly used Valheim mods where practical.
• Pressing the summon key without a selected Forsaken Power safely displays a message and does nothing.

Multiplayer

Boss Spirits must be installed on the server and on every connecting player's client. All players must use the same release version. BepInExPack Valheim and Jotunn are installed automatically when using a compatible mod manager.

Installation

Install with Thunderstore Mod Manager or r2modman. For manual installation, install the listed dependencies and place BossSpirits.dll in a folder under BepInEx/plugins.

Current scope

Version 1.1.0 includes Eikthyr, the Elder, Bonemass, Moder, and Yagluth. The Queen and Fader remain planned for later releases.

Development disclosure

Significant portions of this mod were developed collaboratively with OpenAI Codex. The design, gameplay direction, repeated in-game testing, and final decisions were directed by FalseMods.

Credits

• Iron Gate Studio for Valheim and its original assets.
• The BepInEx, Jotunn, and Valheim modding communities.