Boktai 2 Solar Forging

020093D0 = number of strikes
020093D4 = score
020093D8 = number of GREAT strikes
020093DC = number of GOOD strikes
020093E0 = number of BAD strikes
030046B8 = RNG2 index

Before forge...

If material weapons are the same type, the result weapon will also be that type.
If material weapons are different types, the result weapon will be the remaining type.

Result level = (weapon A level + weapon B level) / 2 (rounded down) + r
- If weapons are same type, r = +6
- If weapons are different types, r = random number between -6 and +6
Result weapon will be the weapon with the highest level less than or equal to the result level.

RNG manipulation trick for two different weapon types:
- Save+reset inside the workshop.
- Talk to Smith and select the first weapon with the A Button.
- Select and then unselect (press the B Button once) the second weapon.
- Repeat the last step until you've reached the weapon with the r-value you want. For example if you want +5, you unselect the second weapon 7 times and then on the 8th time you accept the forge.
-6		 2nd weapon
-5		 1st weapon
-4		 4th weapon
-3		 5th weapon
-2		23rd weapon
-1		25th weapon
 0		20th weapon
+1		11th weapon
+2		 6th weapon
+3		27th weapon
+4		15th weapon
+5		 8th weapon
+6		28th weapon

During forge...

For every hit, score increases by 100 - (amount of pixels you were off)
GREAT = 0-1 pixels off (99~100 score)
GOOD  = 2+  pixels off (60~ 98 score)
BAD   = out of range   (     0 score)

At end of forge...

Your weapon can morph based on the results (rules applied in order, at most 1 rule applied):
- If 0 hits or 10+ BAD hits, you get a Dull Blade, Quarter Staff, or Pounder.
- If Solar Sword and Sword of Darkness, you get Gram, etc.
- If 0-14 hits, chance of R-rank weapon is: 1%.
- If 15+ hits, chance of R-rank weapon is: weapon skill level / 8 (rounded down; doubled if every hit was GREAT) + 1%.
If the weapon advances to R-rank, it will choose the R-rank weapon based on the original resulting weapon's rank and type. Only rank 2, 3 and 4 can advance to R-rank.

If you got 5+ hits and at least 1 GREAT hit, your weapon can become SP level:
SP chance = weapon skill level / 4 (rounded down) + amount of GREAT hits * 3 - amount of BAD hits * 5 + 1%
This chance is used for all 3 of the following checks (you can get all three).
- Check 1: weapon gains its innate SP ability (if it has one)
- Check 2: weapon inherits the innate SP ability of first material (if it has one)
- Check 3: weapon inherits the innate SP ability of second material (if it has one)

If you didn't get any SP abilities, a weapon bonus is calculated at the end of the forge, as follows.

Initial bonus: +6

Adds your skill level for that weapon type divided by 10 (rounded down).

Checks total hits to get your divider:
 0- 9 hits: divider  2
10-14 hits: divider  3
15-19 hits: divider  8
20-24 hits: divider 15
25-29 hits: divider 40
30+   hits: divider 25

Subtracts (hits*100 - score) / divider.
Basically, you get penalized depending on how far off you were from perfect strikes, on average. The more hits you got in, the higher your divider, and the less you get penalized. If you're going for weapon bonus and not SP ability, the optimal number of hits is 25. If you reach 10, 15 or 20 hits, you should only continue if you're sure you can reach the next multiple of 5, otherwise the extra hits will be detrimental if they're not perfect hits (and neutral if they are).

Then, adds the average weapon bonus of both material weapons (rounded down). If a weapon is SP level, it will have a weapon bonus of 0.

Next, divides by 2 (rounded down).

Finally, imposes a limit on your bonus based on number of hits:
 0- 4 hits: bonus at least -10, at most -10
 5- 9 hits: bonus at least -10, at most   0
10+   hits: bonus at least -10, at most +10

Summary:
Weapon bonus is half of the average of your two material weapons, plus your weapon skill level divided by 20 (rounded down), plus 3, minus a penalty based on your number of hits and average error distance.

To get R-rank weapons:
- Forge weapons of rank 2, 3 or 4 (so anything that's not a broken weapon, already an R-rank, a complete weapon or an astro weapon).
- Raise your weapon skill level.
- Try to hit GREATs exclusively.

To get SP abilities on weapons:
- Put in weapons that already have SP abilities.
- Raise your weapon skill level.
- Hit a lot of GREATs.

To get a higher weapon bonus:
- Put in weapons that already have a high bonus.
- Raise your weapon skill level.
- Do more hits (25 is optimal).
- Hit a lot of GREATs or near-GREATs.