Boss names and optional encounter conditions reveal progression and secret objectives. The Bilee and Nibbler sections contain direct spawn instructions.
Fast answer
The answer before the background
The safest approach is to treat every boss as a movement test first and a damage check second. Keep a clear escape route, save stamina for unavoidable patterns, and use area damage to control adds rather than tunnel visioning the boss. Sporelord Rotwood and Bloodsap belong to Linden Forest’s boss pool; Chancellor Autlaic and the optional Bilee encounter are tied to Usvit Depths; Nibbler is an optional giant rat in the same area. The released game also includes later boss encounters such as Velya, Ebon King, Soulus, Lady Nox, Midnight Gatekeeper, Dancing Dragon, Obelisk, and Keeper of Souls. Some exact arena assignments and drops are not published in a complete official list, so this guide labels those details as uncertain rather than inventing them.
Overview
Boss route and what is confirmed
Keeper’s Toll is built around four areas: Linden Forest, Usvit Castle, Usvit Depths, and End of Time. The developer describes each area as having distinct bosses, enemy types, and environmental hazards. The Steam store also confirms that bosses, mini-bosses, and invaders use different mechanics rather than sharing one universal damage pattern.
The safest route through the game is to learn the regular enemy pool before attempting to force damage on a boss. Normal enemies continue to shape the arena, so a build that only has single-target damage can become overwhelmed even when the boss itself is nearly defeated.
- Confirmed named boss or special-boss encounters include Flesh Golem, Sporelord Rotwood, Bloodsap, Chancellor Autlaic, Velya, Ebon King, Bilee, Soulus, Lady Nox, Midnight Gatekeeper, Dancing Dragon, Obelisk, and Keeper of Souls.
- Sporelord Rotwood was introduced as a replacement for Bloodsap during early access, while later released content brought Bloodsap back.
- The official material does not publish a complete boss-by-area table with every reward, so avoid treating community lists as definitive when they conflict.
| Encounter | Verified condition or role | Reward evidence |
|---|---|---|
| Sporelord Rotwood | Linden Forest end-boss replacement introduced during development; remains part of the released boss roster. | Defeat achievement and a Tome of Knowledge task were documented. |
| Bloodsap | Linden Forest boss that was temporarily removed and later returned. | Defeat achievement; exact item drop not officially listed. |
| Chancellor Autlaic | Usvit Depths boss and part of the Black Flame progression. | Defeat achievement; defeating him can infuse the Pyromancer’s robe during that quest. |
| Nibbler | Optional giant rat in Usvit Depths. | Nibbler’s Cheese collectible and achievement. |
| Bilee | Optional Usvit Depths encounter triggered by a skeleton-note quest. | Tome of Knowledge and achievement, according to developer guidance. |
Boss identities and special conditions are verified where the developer or official patch notes state them. Build advice in this guide is practical recommendation based on the documented attack patterns and encounter structure, not a claim that one class or skill is mandatory.
Combat
Counters that work across the boss roster
Use the arena edge only when the boss pattern pushes you there. In most fights, the center gives you more reaction time and keeps summoned enemies from pinning you against a wall. Move in a wide circle, then cut across the arena only when a projectile line or ground hazard forces a change of direction.
Prioritize survivability and reliable coverage over a theoretical maximum-damage build. A short-range hero should reserve an evade for contact attacks and use brief attack windows after a boss finishes an animation. Ranged heroes should keep firing while moving, but should not stand still to complete a long attack if the boss is beginning a telegraphed charge.
Area damage is especially valuable when the fight creates adds, mushrooms, wisps, skeletons, or other hazards. Clear the enemies that block your escape path, then return to the boss. If the arena is safe, focus your strongest cooldowns during the boss’s recovery animation rather than spending them while it is invulnerable or repositioning.
- Keep one movement option available for emergencies instead of using every dash offensively.
- When a boss becomes invulnerable, stop attacking and use the phase to collect experience, reposition, or recover safely.
- Poison, fire, summons, and other damage-over-time tools should be treated as supplemental unless the boss is confirmed to remain vulnerable throughout the effect.
- On Hard Mode, assume faster enemies, higher health, stronger projectiles, and more aggressive boss behavior; the official 1.0 notes confirm all of those changes.
| Threat | Best counter | Common mistake |
|---|---|---|
| Ground hazards or mushroom fields | Circle around the safe space and keep an escape lane open. | Standing still to finish a cast while the hazard spreads. |
| Summoned adds | Use a wide attack or piercing skill to clear the route, then resume boss damage. | Chasing the boss into a corner while adds surround you. |
| Charge or contact attack | Hold stamina for the telegraph and evade through or away from the hit. | Double-dashing early and having no stamina for the actual impact. |
| Invulnerability phase | Stop spending cooldowns and prepare for the next pattern. | Treating a damage-immune phase as a normal DPS window. |
No official source establishes a single best hero for every boss. Choose the hero whose movement and attack range you can control consistently; a familiar defensive build is usually more valuable than a fragile damage build that requires perfect execution.
Optional fights
How to defeat Nibbler and spawn Bilee
Nibbler is the giant rat found in Usvit Depths. Developer guidance states that the encounter requires at least 70 rats to be killed, and the spawn must occur outside a vertical hallway. The developer also stated that Nibbler can have a chance to return after five minutes. A later patch changed his deactivation behavior so that the timer pauses while he is stunned and he disables only when running off-screen.
Do not chase Nibbler directly into danger. Walk away from him while keeping an area attack or other persistent damage effect active. This creates distance from his bite while still damaging him. If he disappears, continue clearing rats and check open horizontal spaces rather than assuming the run is bugged.
Bilee is a separate optional encounter in Usvit Depths. The developer’s instructions say to follow the skeleton-note quest, complete its two tasks, and defeat Chancellor Autlaic within the relevant timing window. After the required conditions are met, a notification and sound indicate that a deep growl has occurred; Bilee then appears roughly three minutes after Autlaic is defeated. The exact wording of the note can be cryptic, so complete its instructions before fighting the boss if the goal is the optional encounter.
- For Nibbler, count rat kills, avoid vertical hallways, and use persistent area damage while walking away.
- For Bilee, read the skeleton note, complete both tasks, then defeat Autlaic before the quest window expires.
- Bilee is not a standard end-of-stage boss. Missing the conditions means the encounter may not appear in that run.
| Optional boss | Encounter plan | Verified reward |
|---|---|---|
| Nibbler | Kill at least 70 rats, stay out of vertical hallways, and keep him in range of area damage while retreating. | Nibbler’s Cheese collectible and achievement. |
| Bilee | Complete the skeleton-note objectives, trigger the growl notification, then defeat Autlaic; Bilee appears about three minutes later. | Tome of Knowledge and achievement, according to the developer. |
Nibbler’s timer and off-screen behavior were changed in a later patch. If an older guide says to stun him continuously or expects a fixed respawn, it may describe an earlier build.
Rewards
Drops, progression, and what is not documented
Boss victories can provide more than ordinary combat rewards. Confirmed progression rewards include achievements, Tomes of Knowledge, and quest-specific items. The Black Flame quest is the clearest example: after defeating the Ebon King as the Pyromancer, the player follows the clue to Usvit Depths, opens the marked chest for the robe, and then defeats Chancellor Autlaic to infuse it and receive the related Tome of Knowledge.
Nibbler’s Cheese is a confirmed collectible, while Bilee is tied to a Tome of Knowledge and an achievement. The official sources checked do not publish reliable per-boss gold, experience, equipment, or drop-rate tables. Treat claims about guaranteed weapons, fixed gold amounts, or exact percentage chances as unverified unless the game itself displays them.
- Defeat achievements are available for several named bosses, including Flesh Golem, Bloodsap, Sporelord Rotwood, Autlaic, Velya, and Bilee.
- End-boss victories can unlock later challenge systems. The 1.0 notes describe Hard Mode as becoming available after defeating the final boss in End of Time.
- Boss rewards may differ by objective, character, difficulty, or platform build; check the post-run reward screen rather than relying on a generic list.
| Reward type | What is verified | What remains uncertain |
|---|---|---|
| Achievement | Named defeat achievements and optional-boss achievements exist. | Achievement names do not prove a unique item drop. |
| Tome of Knowledge | Sporelord Rotwood, Bilee, and the Black Flame route are associated with Tome progression in the cited material. | The complete Tome-to-boss map is not provided in one official source. |
| Collectible | Nibbler’s Cheese is confirmed. | Its broader gameplay effect is not clearly documented in the sources checked. |
| Gold, experience, equipment | Bosses naturally contribute to run rewards. | Exact values and guaranteed equipment drops are not verified. |
If a reward is important for a build, confirm it in the in-game reward screen or a current developer statement. The available official notes describe progression and fixes more reliably than they describe full loot tables.
Planning
How long does a clear take?
There is no official fixed completion time because each run depends on route, deaths, unlocks, difficulty, and how many optional encounters you pursue. A normal clear is best understood as a run-based progression loop rather than a single linear campaign timer.
For a first attempt, budget extra time for learning enemy telegraphs and rebuilding after failed runs. Optional objectives such as Nibbler, Bilee, Black Flame progression, and Hard Mode preparation can extend the process substantially. If the goal is simply to reach the next area, skip optional fights until your build is stable; if the goal is completion, plan dedicated runs around their conditions.
- First clears are slower because experience is spent learning patterns rather than dealing damage.
- Optional bosses can require a separate run because their conditions are easy to miss.
- Hard Mode is not just a health increase: enemies move and attack faster, projectiles become more dangerous, and bosses are more aggressive.
| Goal | Practical expectation |
|---|---|
| Reach the next area | Prioritize movement, experience, and a reliable area attack; skip optional objectives when the run is unstable. |
| Defeat every named encounter | Expect repeated runs because Nibbler and Bilee have special conditions and boss rewards are progression-linked. |
| Complete Hard Mode | Finish the End of Time progression first, then prepare for faster enemies, stronger damage, and enhanced boss attacks. |
A precise hour count would be misleading without a fixed platform, difficulty, and completion target. The sources checked verify the game’s run structure but do not provide an official campaign-length estimate.
FAQ
Common questions
Where do I find Nibbler?
Look in Usvit Depths. Developer guidance says to kill at least 70 rats, avoid vertical hallways, and wait for the giant rat to spawn in a suitable open space. He may have a chance to appear again after five minutes.
Why did Nibbler disappear?
A later patch changed his behavior: his deactivation timer no longer counts down while he is stunned, and he disables when he runs off-screen. Keep him on-screen while dealing damage and avoid chasing him into an unsafe corridor.
How do I spawn Bilee?
Read the skeleton note in Usvit Depths, complete both objectives, and defeat Chancellor Autlaic within the quest’s timing window. A growl notification signals success, after which Bilee appears roughly three minutes after Autlaic dies.
What does Chancellor Autlaic drop?
His confirmed progression role is tied to the Black Flame quest. With the required robe, defeating him infuses it and awards the related Tome of Knowledge. A complete official equipment-drop table is not available.
Is Bloodsap still in the game?
Yes, Bloodsap is part of the released boss roster. He was temporarily replaced by Sporelord Rotwood during early access, then returned in later content.
How long does it take to beat the game?
There is no fixed official time. Your total depends on failed runs, unlocks, optional bosses, platform, and difficulty. A completion-focused playthrough takes longer than simply reaching each area’s end boss.
Sources
What we checked
Official listings establish current availability and product facts. Community pages are used for mechanics and build history, then labeled separately.
- OfficialDeveloper game overview and area information
- OfficialSteam store page and official feature description
- ReferenceOfficial 1.0 release notes and Hard Mode details
- ReferenceOfficial 1.1.10 Steam patch notes
- OfficialDeveloper explanation of Nibbler’s spawn conditions
- OfficialDeveloper explanation of Bilee’s encounter conditions
- CommunityAchievement reference for named bosses and Nibbler’s Cheese