Follow the order: (Except for Legendary Items, take those as soon as possible)

[ Stage 1 ] You don't have mobility. You will take damage at some point, specially during Teleport. Prioritize at least 5 Tougher Times.

- 5x to 10x:

Tougher Times

[ Stage 1 to 4 ] Build up attack speed for faster charging and AoE damage for clean ups. Lifesteal, shield and mobility to help with survival.

- 5x:

SyringeCrowbarBackup MagazineLens Makers GlassesPaul's Goat HoofOld GuillotineUkeleleWill O' The WispHarvester's ScytheAtG Missile MK. 1Topaz BroochLeeching Seed

[ Stage 3 to 6 ] You can kill most enemies easily with low risk. Keep focusing in survival tho. Enemies start to become lethal and tanky.

- 15 to 20x:

Tougher Times

[ Stage 6 ] At this point you must at least have all of these.

- 9x to 10x:

Lens Makers GlassesCrowbarArmor Piercing RoundsStun GrenadePaul's Goat HoofSyringeOld GuillotineUkeleleWill O' The WispHarvester's ScytheAtG Missile MK. 1Topaz Brooch

[ As soon as possible ]

Ceremonial Dagger will automatically kill weak enemies, so you can focus attention on stronger ones.

Brilliant Behemoth, Shattering Justice and Resonance Disc will greatly facilitate killing enemies with higher HP.

Aegis helps survival.

Alien Head, Sentient Meat Hook, Happiest Mask will support your build.

- 1 of each:

Ceremonial DaggerBrilliant BehemothAlien HeadSentient Meat HookAegisHappiest MaskShattering JusticeResonance Disc

[ Stage 7+ ] For the rest of the run you can keep stacking these:

SyringeCrowbarPredatory InstinctsAtG Missile MK. 1UkeleleWill O' The WispTougher TimesGasoline

As for Active Items take any of your liking (Buzz Saw wasn't in the list but it's included):

Primordial CubeDisposable Missile LauncherThe Back UpRoyal CapacitorEccentric Vase

Others you may take as well

Titanic KnurlLittle DiscipleHalcyon Seed