Summary:
- Helix merits do affect helix II spell damage in the same way they affected helix I damage. 5/5 corresponds to 10% increase in total damage
- The max base damage (where the dINT contribution to damage is capped) is 225
- Base damage ("V") appears to be 75 (dINT = 0)
- M (the modifier for dINT) is 2 between dINT = 0 and dINT = 50, and M = 1 after dINT = 50 and probably up to dINT = 100 if the max base damage caps at 225. M can be considered 0 after dINT = 100 (dINT does not contribute to damage after dINT = 100).
- Dark Arts adds 24 base damage to Helix II spells, as it does to Helix I spells
SCH99/RDM49
Given 427 MAB and 259 magic damage (also 340 INT) on Tiny Mandragora (INT 6), I observed the following damage with 5/5 Helix group 1 merits and no other bonuses (like Dark Arts or weather) or penalties (weather):
Geohelix: 2549
Geohelix II: 2805
Since helix I base damage caps at 181 (dINT 234 or greater), the observed value matches the calculated value:
181+259 = 440
440*(1+4.27) = 2318.8 => 2318 (floored to nearest integer)
2318*1.1 = 2549.8 => 2549 (floored to nearest integer)
Based on the above, helix II base damage probably caps at 225. 2805/1.1/5.27 - 259 = 224.8
Removing all merits, I get 2318 Geohelix and 2550 Geohelix II. Calculating Geohelix II damage with 0/5 helix merits, (225+539)*(1+4.27) = 2550.68
Stripping away INT and all MAB and magic damage from equipment leaves 114 INT and 60 MAB (0 magic damage). I got 188 Geohelix and 360 Geohelix II. For helix I, the calculated damage matches:
(103+(114-6-78)*.5)*1.6 = 188.8 => 188 rounded down.
However, Geohelix II base damage still appears to be capped at 225... (225)*1.6 = 360. So the dINT contribution to damage stops at dINT 108 or below.
...
Moving on... it is known that level 124 Metalcruncher Worms have 292 INT. Given this and 389 MAB and 239 magic damage and dINT = 0, I get 1290 Pyrohelix and 1535 Pyrohelix II.
Pyrohelix total damage calculation: (25+239)*(1+3.89) = 1290.96 => 1290 (still have 0/5 helix merits), so this corroborates dINT = 0 as expected.
Pyrohelix II base damage calculation: 1535/(1+3.89) - 239 = 74.9. So the base damage of helix II seems to be 75 (dINT = 0).
From 75 at dINT = 0 to 225 at "capped" dINT (108 or below), the dINT contribution thus must be capped at 150.
...
Moving on... it is known that level 126 Metalcruncher Worms have 312 INT. Given this and 415 MAB and 259 magic damage and dINT = 20 (INT 332), I get 1565 Pyrohelix and 1926 Pyrohelix II.
Pyrohelix total damage calculation: (25+1*20+259)*(1+4.15) = 1565.6 => 1565. This confirms dINT = 20 is correct.
Pyrohelix II M calculation: (75+M*20+259)*(1+4.15) = 1926 (after rounding). Assuming that M is indeed constant between dINT = 0 and dINT = 20, solving for M, M = (1926/(1+4.15)-259-75)/20 = 1.999, so M appears to be 2 from dINT = 0 to dINT = 20 at least.
M can't possibly be 2 from dINT = 0 to dINT = 100 (75+200 = 275, which exceeds the cap of 225).. this could be explored later. I noticed that for this post on FFXIAH (http://www.ffxiah.com/forum/topic/47...amage/#2951613), if you select an inflection point of dINT = 50 and M = 1 after dINT 50, I can calculate 261 damage with 0/5 merits)... (75+100+1*(88-50))*1.23 = 261.99 => 261... I can look into this on Ebony Puddings (89 INT) at a later time
Finally, under Dark Arts, I get 1689 Pyrohelix and 2049 Pyrohelix II, same level 126 Metalcruncher Worm (312 INT), same 415 MAB and 259 magic damage and dINT = 20 (INT 332). We know Dark Arts adds 24 base damage to Helix I.
Pyrohelix total damage calculation: (25+24+1*20+259)*(1+4.15) = 1689.2 => 1689. This confirms that Dark Arts does still add 24 base damage.
Pyrohelix II total damage calculation: (75+24+2*20+259)*(1+4.15) = 2049.7 => 2049 (after rounding). This confirms that Dark Arts adds 24 base damage also to helix II spells.
Edit: checking the range of M for helix II
Level 75 Ebony Puddings in Mount Zhayolm have 89 INT. They also take 25% more damage from magic damage. Given this and 60 MAB, 0 magic damage and dINT = 25 (INT 114), I get 100 Anemohelix and 250 Anemohelix II
Anemohelix damage calculation: ((25+114-89)*1.6)*1.25 = 100
Anemohelix damage calculation: (((75+2*(114-89))*1.6)*1.25 = 250, so M = 2 from dINT = 0 to dINT = 25 at least
Adding INT+25 and MAB+48... 195 for helix and 455 for helix II
Anemohelix damage calculation: ((25+114+25-89)*2.08)*1.25 = 195
Anemohelix damage calculation: (((75+2*(114-89))*2.08)*1.25 = 455, so M = 2 from dINT = 0 to dINT = 50 at least.
Adding INT+28 and MAB+48... 202 for helix and 462 for helix II
Anemohelix damage calculation: ((25+114+28-89)*2.08) = 162.24 => 162. 162*1.25 = 202
Now I suspect after dINT = 50, M = 1. If this is true, then after dINT = 50, damage is calculated as follows:
(175+1*(114+28-89-50))*2.08 = 370.24 => 370. 370*1.25 = 462.5 => 462
Then extrapolating linearly to dINT = 100 (in this example, 114+75-89 = 100), helix base damage would cap at 225 (175+1*(114+75-89-50)) when dINT = 100.