So like a dumb ass, I went and upgraded all of the 8 bit weapons at much time and expense. Here’s my verdict on what is a good investment. All weapons that are excluded either have a better counterpart or just not special enough to warrant the grind. These will be judged based on their contemporaries. Obviously nothing can compete with the crissagram v2 or oracle sword.
Sculptor’s chisel: with attack 46 and ice element on it, this is basically the ice version of the holy gae assail but with petrification on top of it. IMO the best 8 bit weapon as it is a strict upgrade to the best in its class.
Oleanders: attack 36 is second tier in terms of attack, but it’s poison more than makes up for it. Shoes attack fast too so lots of tick damage on top of it. Very nice shoes if you use them.
God cross: attack 36 in final form is not good but it’s energy blast covers the whole length of the map which is rare. Most only travel a small distance and hit the ground at an angle. It also has the odd combo of holy and petrification. Really a one of a kind weapon. There are only 4 weapons in the game that do petrification, and two of them are 8 bit weapons. The murgleis is the other sword that does it but God cross has 11 more attack and holy (which many demons are weak to) on top of it. Which makes it second only to the crissagram and maybe ridill IMO.
Eu’s sword: attack 58 which puts it on par with Blue Rose albeit without the ice element on it. Debatable if the nightmare or the imbrued fang is harder to farm. Neither can really compete with the Ridill or Rhava velar (crissagram v2). Still it’s an 8 bit weapon with top attack rating.
Encrypted orchid: it’s not great with only 46 attack, but compared to the yagrush and the caladbolg, the two top thunder swords, it is better in its niche. It’s energy blast is point blank and it hit multiple time. Plus its a purple lightsaber with the same sounds. It’s just a cool weapon ok?
Deathbringer: attack is second tier compared to eternal blue but better than ukonvasara. In fact, out of the great axes, it attack is top tier, just can’t match the top great swords. It hits three times which I think makes up for it. Especially in the early to mid game.
Blood grinder: same spot as deathbringer with second tier damage. But it has curse on it which automatically makes it better dps to enemies not immune to curse.
Silent calamity: it’s attack isn’t great, tipping off at 50 but it’s petrification makes it unique. The Kaladanda is another great sword with petrification but with 4 less attack. Kaladana also needs gold to make although I recall it can be picked up late game from a chest. Silent calamity has potential to be gotten earlier.
Edit: Claw of Onmorki: this weapon has sub par attack but it does have the unique charge up attack and seems to hit faster even in its base form. I’m not really sure since I have G9R9 on great sword expertise and optimizer. If so, then this weapon might be a great early investment but falls behind late in the game since expertise and optimizer will bridge the difference.
Edit 2: Ambivalence: this whip seemed like a clone for the ultimate whip (same stats) but I just learned from a u/laitomenow, that you can switch between dark and holy by using a charged attack. This versatility easily makes it the best whip and an easy pick if you’re into whips.
Renee’s Requiem: hands down the best stats among guns with 32. Compared to Adrasteia’s 26. Adrasteia does have homing bullets that make it much easier to use on smaller and/or more mobile targets. Adrasteia can also shot through walls! But as u/SDMayo pointed out, this homing will work against you on targets that have to be hit on a specific point. Like the 8 bit overlord that you farm the nightmare from. As a straight shooter this is by far the best with its sheer attack advantage. Using diamond ammo with 494 attack on a morte Adrasteia did 545 while the Requiem did 567. Still for 95% of the demons out there Adrasteia is just easier to use. This is debatable in my mind but should be noted.