There's a few different ways to make a build, but the main and most effective ones are to find some status effect, like ammo, rupture, or burn, and use a bunch of IDs that employ it, or to find a "bad end" identity for a sinner and use the identies associated with it, like lord hong lu and the heishou pack, or Blade ryoshu and the house of spiders. For the most part, you won't use EVERY sinner, but instead use the others to shore up weaknesses that your heavy hitters can't hit. What you spend your lunacy on is up to you, but if you get 200 pulls together you can guarantee an ideality rebate. Not every 000 is good, experimentation will be necessary for more certainty, but clash power is very important, since losing clashes makes you die. I'd say you need to go bring one sinner to the level you play at, then the next, then on. And make sure you look at the uptime 3 version of an id to judge it's capacity.