BossAdd

BossAdd

BossAdd adds new mechanics and phase patterns to Valheim's bosses.

Every feature is fully configurable via BepInEx ConfigurationManager (F1 key).

Supports English and Korean — auto-detected from your Valheim language setting.

Development status: Eikthyr, The Elder, Bonemass, Moder, and Yagluth are fully

developed. The Queen and Fader are planned for a future update and currently only

get the generic Boss Stat / Summon options shared by every boss.

Balance note: Starting with this version, each boss's default settings have been

tuned to fit the difficulty of the biome it's fought in, based on extensive

playtesting — rather than arbitrary placeholder numbers.

Features

Eikthyr

• Summon — Calls minions on HP thresholds, timer intervals, or both. Includes a special elite summon at low HP.
• Stomp Lightning — Stomp attacks trigger lightning strikes with a configurable burning DoT on hit and a safe zone radius. Once active, lightning also starts crackling along the boss's own body (size and how far it spreads from the body are both configurable).
• Horn Attack — Horn charge launches players with force matching the boss's actual melee attack range. Blocked while the player is dodge-invincible. Once active, the horns themselves glow.
• Activation Effects — The first moment Horn Attack or Stomp Lightning turns on, a one-time lightning-strike visual plays on Eikthyr itself (purely cosmetic, no damage) — a little "power-up" moment to mark the transition.
• Phase Messages — Custom HUD messages at configurable HP thresholds.

The Elder

• Tree Spawn — Grows trees around players when below HP threshold. Once active, the boss's own body darkens to a charred color.
• Rock Throw Combo — The root-shoot attack triggers a configurable burst of boulder throws (count and interval), each with splash damage on impact. Once active, the boss's body stripes start glowing red.
• Activation Effects — The first moment Tree Spawn or Rock Throw turns on, a one-time visual plays on the boss itself (purely cosmetic, no damage).
• Phase Messages — Custom HUD messages.

Bonemass

• Split Summon — Splits into 5 MiniBonemass variants at HP threshold.
• Kill Condition — Bonemass cannot die until all 5 MiniBonemass are defeated, in a set color order (configurable). Minis out of order still take damage normally, but a hit that would kill one instead "saves" it at 50% HP and heals Bonemass itself a bit (configurable), with a message and a visual effect at Bonemass's own position. Optionally, Bonemass itself can be made fully invulnerable (including to damage-over-time) while any mini is still alive. Fully synced in multiplayer — every player sees the same order enforcement and healing, not just the host.
• Mini Stats — Customize MiniBonemass HP, damage, speed, attack range, and damage resistances independently.
• Mini Leash — Minions that wander too far from the main body are teleported back near it, so they can't be kited away indefinitely (configurable distance).
• Always-Visible Nameplates — MiniBonemass names are always shown, not just when directly aimed at.
• Throw Summon — Throw attacks have a chance to spawn additional minions. The throw attack itself can now be blocked with a shield.
• Phase Messages — Custom HUD messages.

Moder

• Air Breath — Fires frost breath while airborne. Deals damage continuously for the duration of the breath (tick rate, duration, damage, and knockback all configurable) instead of a single hit, can be blocked or dodged throughout, and staggers you on a solid hit. Once active, Moder's fur takes on an icy blue tint.
• Ground Breath — The dragon's grounded breath attack works the same way — continuous multi-hit damage for as long as the breath lasts, blockable/dodgeable the entire time, and staggers on impact.
• Dragon Shockwave — Landing (and now taking back off, too) sends out an expanding shockwave ring that follows the shape of the ground. Anyone caught in it takes blunt damage and gets knocked back — blockable (still knocks you