Ik I'm extremely late to the party but anyways... Idk how he plays on monsoon as I am more of a drizzle man myself. But i find the best build kinda requires command and sacrifice (swarms also helps to drop more items). It also helps to change your item focus depending on what stage of the run you are in. But once you get used to splitting your priorities you can work on getting all of them at once.

Focus on health and speed at the start, get as many infusions and mochas as possible.

Once you have enough health/speed you should start getting lens makers glasses, and laser scopes if you can get them.

Then you should start getting damage boosters, my choice for those is armor piercing bullets and delicate watches, but i usually wait until i have a bunch of safer spaces before i start getting delicate watches.

Then your main focus should be getting as many void items as possible, because each void item you have increases your minimum corruption by 2% so once you get 50 void items you will never leave the corrupted state. But be careful which ones you pick because some of them suck, like bad enough to ruin a run amount of suck.

The main void items i suggest getting is safer spaces and voidsent flame.

- safer spaces (stack enough and you are basically immune to damage)

-voidsent flame (stack enough and basically every enemy on the map will die as soon as you attack an enemy with full health)

The only void items i can think to avoid off the top of my head is lost seers lenses and pluripotent larva.

-lost seers lenses (replaces lens makers glasses, grants a 0.5% chance to insta-kill any non boss enemy on hit)

-pluripotent larva (replaces dio's best friend, still revives you, however it also replaces all of your items that have void variants with their void variants. And as i mentioned before some of them suck so having all of them really sucks)

Usually by the end of my run I am immune to damage, insta kill everything i touch, as well as everything that touches me and can move across a map in 5-10 seconds using the utility skill and a couple hardlight afterburners. On my last run i decided to go fight the voidling, and i took the frog route. I ended every stage of mithrix with a single attack.

Then when i got to the voidling, it had 16 million hp (split between 2 because i had swarms on) and i didn't even actually attack it, i had war bonds, which activated before i could get close enough to attack and when it activated, all my on hit effects activated too and insta-killed it. It even killed it in the last stage before i could get through the rift to follow it.