Honestly at Scolexis, it isnt that hard.
When i saw your comment i went into the game, did one run and just finished the blade first try.
Never attempted it before really.
You need some unlocks/buildings, but in fact RNG wasnt going well with me and i still got it going.

Nosferatu is far tougher to get, considering you need 4 evolutions to exactly line up and you need 27 level ups entirely dedicated to your balls (6x3 for basic balls, then x3 for the 3 evolutions).
You need the exact combination of balls, level them up and evolute them at the right time.

Getting 4 specific passives is only tough because you cant just fuse them to make space.

nice game !

@Soviet - Nice catch, added

@Scolexis - Damn, sadge indeed. Guess it's just up to RNG at that point

Yeah I've got the 5th passive slot, almost finished with the entire NG+ and still haven't been able to get it. I've done tons of run banishing all passives, and saving my re-rolls for when I really have nothing else to pick to waste the choice to optimize the most passive drops. Closest I got was all 4 but it was at the last boss so I didn't get anymore fusions...
Sadge.

A small thing, you are missing Light X Lightning, but you do have Lightning X Light

Doubt certain characters increase chances, at times I never saw more than two knives a run as if the game knew.

As for tips I'd say maxing banish + free rerolls, banishing other passives, and unlocking the 5th passive slot.

Deadeye's Cross is impossible to get, I've done so many runs and can never get all the pieces. Any tips? Do certain characters roll those passives more than others?

my favs, Blackhole x Sun and Overgrowth x Lightbulb.

That is true, will find and add what I can see

There's also passive combos. The only one I've found so far was:
War Horn x Baby Rattle - > Cornucopia

That might need its own section. I have an inkling that if you get all 4 hilted daggers, that would also evolve, but getting all 4 and leveling all of them up is quite the task.