BillionNemesis

(Lust update) Adds alternate verions of levels with higher difficulty and more interesting enemy arenas

By BillyMod

Date uploaded	a week ago
Version	2.0.0
Download link	BillyMod-BillionNemesis-2.0.0.zip
Downloads	1166
Dependency string	BillyMod-BillionNemesis-2.0.0

This mod requires the following mods to function

BepInEx-BepInExPack

BepInEx pack for Mono Unity games. Preconfigured and ready to use.

Preferred version: 5.4.2305

Hydraxous-Configgy

Library mod for configuring other mods!

Preferred version: 1.0.7

BillyMod-SpawnerArmExtras

Unlocks missing enemies in the sandbox + adds new custom ones. Now also works for cheats

Preferred version: 6.0.1

README

Billion Nemesis is a mod aims to redo all the arenas in the game by making them more interesting and a lot harder (not meant for a new save). Kind of like Encore levels except it all takes place in the original levels instead of brand new ones (Use Configgy to switch between Nemesis and vanilla)

If you find any bugs or have other feedback (or maybe custom enemy ideas?) then dm me on discord @somebilly, also make sure to check that you have the latest version of SpawnerArmExtras installed (v6.0.0) since having an older version will also cause issues with this mod

Features

Currently all campaign levels from 0-1 to 2-4 have new encounters
Each layer gets progressively harder than the last
Limited use of radiance or enemy spam
New names for the levels and occasional level environment changes
Hidden terminals with "dev commentary" in each Nemesis level
So-called custom enemies

(If you don't have any electric weapons, you can walk into an electric coil to activate it)

Information

Generally I tried to use interesting enemy combinations and to play into the environment/level geometry so that you approach things in more unique ways and such. The new encounters aren't limited in enemy types and late game enemies can appear from the very start. So I recommend beating Fraud if you haven't done that yet.

Nemesis levels save your progress separately and they have their own rank requirements

Custom enemies

1. Black Hole Launcher (Limbo)

(Introduced in 1-2)
(27 health) Fires 1 slow black hole at a time that constantly follows you. Requires you to keep track of its position and to keep moving. If you get hit by the black hole, the launcher will fire the next one 2 seconds later

I know that the black holes don't target you through portals but I don't know how to fix that lol

2. Watchtower (Limbo)

(Introduced in 1-3)
(30 health) A tall defense system tower that shoots series of projectiles which predict your movement. If you parry any of the projectiles in the series, the rest will become purple which means they're now unparriable and don't deal damage to enemies. The yellow orb at the top can be parried to deal 10 damage to the Watchtower, either with the feedbacker or the jackhammer. Trying to parry the yellow orb may be dangerous, but it helps to kill the Watchtower a lot quicker

3. Fuchsia (Lust)

(Introduced in 2-1)
(16 health) Fires 2 magenta beams back and forth, can't be whiplashed. When you get too close it either: 1) pushes you up if it has wings, 2) pushes you down if it has a crown, 3) damages you if it has neither. Go read the full description under SpawnerArmExtras

4. Enrager (Lust)

(Introduced in 2-2)
Idol-like enemy that enrages the target enemy until it's broken. If the target enemy can get enraged on any higher difficulty, then it will still enrage even on lower difficulties.

5. Shockwave Shuffler (Lust)

(Introduced in 2-2)
(15 health) Creates magenta shockwaves every few seconds (the shockwave speed, size and cooldown can vary)

6. Puppeteer (Lust)

(Introduced in 2-3)
Idol-like enemy that creates puppets of the target enemy until it's broken. The cooldown depends on difficulty. In specific encounters, the puppets may not die when the Puppeteer is killed. And the puppet spawning cooldown can also be different on a case-by-case basis

Wait!

Currently the mod is in development, so only some layers are changed. I'll update it as I finish each layer (if it's been like a week or more since the last patch then i'm probably working on the next layer already)

I'll most likely make the first 2 layers of every act similar in difficulty to avoid everything getting hard too fast

Done (3/10) - 13 levels

0. Prelude
1. Limbo
2. Lust

Upcoming (7/10) - 22 levels

3. Gluttony
4. Greed
5. Wrath
6. Heresy
7. Violence
8. Fraud
9. Treachery
Prime Sanctums? (maybe but only after treachery)
Encores? (maybe but only after all encores come out)

if you can p rank everything in Billion Nemesis on Billion Difficulty i'll be impressed

CHANGELOG

Version 2.0.1 (2026-06-23)

(0-1) Added a popup telling you to not use a new save
(2-1) Maybe fixed Insurrectionists getting stuck on stairs
The thing where electric coils would activate without the needed weapons still didn't work after trying to fix it multiple times so i'm just removing it
(not actually relevant yet but) Fixed Fuchsias and Shockwave Shufflers acting weirdly when puppeted or radiant
Gave Fuchsia a small telegraph before it starts firing its lasers

Version 2.0.0 (2026-06-21)

Added Nemesis levels for Lust (2-1, 2-2, 2-3, 2-4)
(0-1) Updated the title drop
(0-4) Fixed 2 Streetcleaners in the last arena spawning at the same position
(1-2) Fixed missing fire and title drop
(1-2) Fixed a checkpoint not resetting a room
Deathcatcher cases lose their collision when opening for convenience and to prevent possible bugs/getting stuck
Black Hole Launcher's black hole speed now depends on difficulty
Maybe fixed the electric coil activation if you don't have electric weapons
Time rank requirements that appear in the console when you start a level now show time in a readable format
Corrected the listed number of health for Black Hole Launchers in the mod description
Removed unneeded bits of some elevator textures to reduce the size of the mod
Added logo to the mod description

Limbo - 1.x.x (2026-05-19 to 21)

Version 1.2.0 (2026-05-21)

If you don't have the jumpstart nailgun or electric railcannon, you can now activate tesla coils by walking into them (great news for the 3 people playing this on a fresh save)
(0-3) Made the enemy trigger activated by the tesla coil bigger
(1-2) Added a checkpoint in the blue skull room because i didn't know how to fix a softlock there
(1-3) Fixed enemies in the blue skull arena getting stuck in the corner
Reduced Black Hole Launcher health from 30 to 27
Increased Watchtower hitbox size
Increased Watchtower yellow orb parry damage from 10 to 12

Version 1.1.0 (2026-05-20)

(0-1) Recolored the pit at the beginning of the level
(0-2) Added a checkpoint at the end
(1-1) Added a checkpoint before the final room
(1-3) Added an extra hookpoint in a specific arena
(1-3) Delayed spawns in the last arena
(1-3) Fixed the rotation of torch pedestals and slightly moved an Idol in the last arena
(1-4) V2 won't get enraged until its idol is broken
(1-4) Fixed Virtue not enraging after you died once
Made Watchtowers wider

Version 1.0.0 (2026-05-19)

Added Nemesis levels for Limbo (1-1, 1-2, 1-3, 1-4)
Added level 0-5
The hellevator rooms are now pink
Layers and chapters (acts) that are fully P ranked on Nemesis now also have a pink rank background
Made some Idols spawn before the enemies they're protecting instead of after
Powers without an intro now have a spawn effect like other enemies
Mirror Reaper goop doesn't damage enemies
The subtitle in 0-1 should be less broken on different resolutions
Changed commentary 4 to mention commentary 1 instead of 2 since that was incorrect
(0-1) Moved the fan upwards in the room before the boss
(0-3) Made the speed of the series of beams depend on difficulty
You can now see what's currently being loaded in the console when the game is starting
Updated the mod description

Prelude - 0.x.x (2026-04-22 to 24)

Version 0.3.0 (2026-04-24)

P rank backgrounds are now pink on the level end screen as well
(0-2) Some changes in the final arena + the enemies can no longer be killed by the crushers + increased the time requirements by a bit
(0-3) Fixed a niche softlock in the room with lots of beans
(0-4) Made the lower ranks' kill requirements smaller, this doesn't actually affect anything because you still need to kill all enemies to beat the level but I didn't like that you stay at a D rank until the skull arenas

Version 0.2.1 (2026-04-23)

Updated the icon

Version 0.2.0 (2026-04-23)

(0-4) Added to the first arena and the blue skull arena, and also changed the rank requirements to account for this
Updated the mod description to mention the secret terminals
Fixed Powers potentially not doing anything after you die and respawn
(0-2) Fixed the short crusher hallway not being loaded when you respawn at the checkpoint before it
(0-4) HOPEFULLY fixed the electricity box not being breakable sometimes (you still need to kill the enemies first)

Version 0.1.2 (2026-04-22)

(0-4) Fixed softlock

Version 0.1.1 (2026-04-22)

(0-2) Fixed a softlock (thank you kind stranger!)

Version 0.1.0 (2026-04-22)

Initial release (0-1, 0-2, 0-3, 0-4)

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