Endless Mode

Endless Mode is one of the Game modes in The Metronomicon. It is unlocked by beating the boss of Story Mode for the first time.

Description
Unlocked by beating the Story Mode boss, battle against an unlimited playlist of songs as the enemies' levels slowly increase, and a variety of mods get stacked against you. Use and swap through your entire team and all their skills to combat hero knockouts, equipment breaks, and even skill lockouts. Gain and spend Battle Points to empower your current run, or save them up to unlock permanent cross-mode rewards. The faster you go, and the more mods that are applied, the more points you'll get. However! Fail to defeat a song's boss before it ends, and your run is over. Stack more mods early, while the enemies are weaker, to build up battle points. Or! Run, afraid, from modifiers, to get as deep as you can! Two leaderboards exist!

Mechanics
Initially, you start out the mode with a completely clean party of 4 members. After you beat a song, you earn an amount of Battle Points, and a mod is added that, depending on your playstyle, can be mildly annoying or a huge inconvenience. From there, you are presented with a perk shop, where you can buy perks that either help you, or make the songs more challenging. As you progress further, the perk costs (with the exception of Add a Mod) gradually increase. If any characters were knocked out, you can travel to the Inn to replace them for free; else, you would have to pay a Battle Point cost to travel to the Inn.

Songs are randomly selected from all the songs that you own, including base game and any purchased DLC songs, but excluding UGC and Deck the Dubstep. Every 10th song will be a Boss song. After the 10th song, 2 mods will be added after each song; after the 20th song, 3 mods will be added. Battle Points per song are calculated based on how many active mods there are, any speed bonuses for finishing the song before a certain cutoff, and then multiplied by any challenge multipliers that were purchased from the perk shop.

The perks for sale in the perk shop are randomised after each song. Without More Options purchased, you only have a total of 7 to pick from; with More Options purchased, that total grows to 10. The number of perks to pick from are split accordingly:

Without Second Choice, you can only buy 1 perk; with Second Choice, you can buy 2.

When adding a mod, you can pick from 1 of 3 randomly selected mods, but your purchase is already locked in when bought. Likewise, when removing a mod, you're allowed to pick the mod you can remove, but your purchase is already locked in when bought (which is crucial as the prices for this can get really hefty in the endgame).

If you are unable to afford a perk with the BP you have in this run, you can opt to spend your BP that you have already banked from ending runs, at six times the cost. The maximum BP that you can bank is 100,000.

Team Attack/Health

 * Refill 50% Health/Refill Health to Full
 * Fill 50% Team Attack/Fill Team Attack to Full

Buffs

 * Auto-Inspire/Focus/Haste Team
 * Slow all Enemies
 * Damage Resist +20%
 * Damage +20%

Debuffs

 * Permanent Mines (50% bonus next song)
 * Permanent Boulders (85% bonus next song)
 * Skip Next Purchase Chance (60% bonus next song)
 * Disable All Equipment (75% bonus next song)
 * Lock Out Secondaries (75% bonus next song)
 * Enemy Level +.5 or +1 (65%/80% bonus next song)

Add/Remove Mod

 * Add one mod
 * Remove one mod

Note that the cost to removing a mod increases the further you go in, but the cost of adding one mod remains consistent.

Also, without More Options purchased, you can either add or remove a mod, but not both, and the choice of which is randomly determined.

General

 * Start out both strategies amassing as much BP as possible, so you have greater spending flexibility in the endgame
 * This means you try to add as many debuffs as you can feasibly handle
 * If you're uncomfortable with a certain debuff, try adding a mod instead - it won't immediately pay back the investment, but will do so after a few songs
 * If all your Secondaries are locked out (whether by ability lockout or Hazy) and you don't have Gruver's Gift in play, buying the debuff that locks out secondaries is a no-brainer for extra BP
 * Likewise, if all your equipment is shattered, buy the debuff that disables all equipment
 * Because you need to beat the songs before they end, try utilising some strategies from GOTTAGOFAST
 * A stunlocking build is amongst one of the safest builds to use, especially endgame, and has a decent song clear speed
 * Try starting off with the worse party so you can attempt to finish off the run with your stronger party; note though that it is entirely up to RNG when it comes to characters being knocked out
 * If you're having trouble using Pierce effectively in a party build, try using his Backstab to inflict Bleed, which will deal damage over time and can potentially chain into abilities like Bloodhound
 * Because Secondary abilities can, and will, be locked out, use Gruver early on to get the most out of his Gift
 * Or, if you're using Phantom Time, again use him early before more and more Primary abilities get locked out

Most BP

 * Do not waste too much BP buying buffs or removing mods - if possible, avoid buying buffs or removing mods altogether
 * Instead, try to tank all the debuffs as much as you can
 * If you find multiple debuffs challenging to handle in terms of reading notes, try downgrading to a lower difficulty
 * Near the end of the run, only buy debuffs if they will cause minimal impact; else it is advised to avoid buying anything altogether

Most Songs

 * Remove mods which you feel are detrimental to your gameplay (note judgment tightens for example can be brutal if multiple are in play)
 * Try buying buffs late-game as more abilities are locked out and characters are deleveled too much in order to finish the song on time

Rewards

 * Passive Abilities can be unlocked in Endless Mode, for use in all game modes.
 * Battle Points can be saved and stocked for use in later runs, making even deeper songs possible.
 * Flavius can only be unlocked via this mode - see his page for the procedure.