We should probably update the guides/what we tell people based on the high cost of heating 5* weapons

vs depth 24 slag (piercing neutral)
normal, charge
Strike Needle level 10 (High bonus)
68 194
Strike Needle level 10 (VH bonus)
72 206
Blitz Needle level 1 (VH bonus)
56 151
Blitz Needle level 2 (VH bonus)
57 153
Blitz Needle level 3 (VH bonus)
58 158
Blitz Needle level 4 (VH bonus)
59 162
Blitz Needle level 5 (High bonus)
58 158
Blitz Needle level 5 (VH bonus)
61 169
Blitz Needle level 5 (Max bonus)
67 189
Blitz Needle level 6 (VH bonus)
64 179
Blitz Needle level 7 (VH bonus)
67 188
Blitz Needle level 8 (VH bonus)
70 198
Blitz Needle level 9 (VH bonus)
74 209
Blitz Needle level 10 (VH bonus)
77 221
vs depth 24 trojan (piercing weak)
normal, charge
Strike Needle level 10 (High bonus)
126 259
Strike Needle level 10 (VH bonus)
133 271
Blitz Needle level 5 (VH bonus)
111 234
Blitz Needle level 6 (VH bonus)
117 244
Blitz Needle level 7 (VH bonus)
123 254
Blitz Needle level 8 (VH bonus)
128 264
Blitz Needle level 9 (VH bonus)
135 275
Blitz Needle level 10 (VH bonus)
142 286

vs depth 25 trojan (piercing weak)
normal, charge
Strike Needle level 10 (VH bonus)
137 281
Blitz Needle level 5 (VH bonus)
115 243
Blitz Needle level 6 (VH bonus)
121 254
Blitz Needle level 7 (VH bonus)
127 264
Blitz Needle level 8 (VH bonus)
133 274
Blitz Needle level 9 (VH bonus)
140 286
Blitz Needle level 10 (VH bonus)
147 298
vs depth 26 trojan (piercing weak)
normal, charge
Strike Needle level 10 (VH bonus)
137 284
Blitz Needle level 5 (VH bonus and damage pickup) I didn't notice a damage pickup but I must have gotten one
154 314
Blitz Needle level 6 (VH bonus)
123 260
Blitz Needle level 7 (VH bonus)
129 270
Blitz Needle level 8 (VH bonus)
135 281
Blitz Needle level 9 (VH bonus)
142 293
Blitz Needle level 10 (VH bonus)
149 305
vs depth 27 trojan (piercing weak)
normal, charge
Strike Needle level 10 (VH bonus)
137 286
Blitz Needle level 5 (VH bonus)
120 259
Blitz Needle level 6 (VH bonus)
127 270
Blitz Needle level 7 (VH bonus)
133 281
Blitz Needle level 8 (VH bonus)
140 292
Blitz Needle level 9 (VH bonus)
147 304
Blitz Needle level 10 (VH bonus)
155 317

vs Vana (piercing weak)
normal, charge
Strike Needle level 10 (VH bonus)
76 223
Blitz Needle level 5 (VH bonus)
70 200
Blitz Needle level 6 (VH bonus)
73 211
Blitz Needle level 7 (VH bonus) // I had 233 for charge, but I think it was a typo. It's wierd that the first damage is 77 instead of 76 though
77 223
Blitz Needle level 8 (VH bonus)
80 234
Blitz Needle level 9 (VH bonus)
85 248
Blitz Needle level 10 (VH bonus)
89 261
vs Mask (piercing resistant)
normal, charge
Strike Needle level 10 (VH bonus)
64 155
Blitz Needle level 5 (VH bonus)
59 133
Blitz Needle level 6 (VH bonus)
61 143
Blitz Needle level 7 (VH bonus)
64 155
Blitz Needle level 8 (VH bonus)
66 169
Blitz Needle level 9 (VH bonus)
69 193
Blitz Needle level 10 (VH bonus)
72 211

Wow, that's a lot of data. O_O
But the way that weapons work with higher * ones doing worse makes no sense, if you want to keep higher gear weapons from being OP in lower tiers just make them less effective, but more so than their lower * versions. A 5* weapon at any heat level should always do at least a little bit more damage than a 4* at level 10--and at any level in the clockworks.

Bopp, I think level 5 is way too low as a general sword upgrade level. I would recommend at least level 8 or 9 unless it really gains something extra like Acheron damage or more projectiles like the brandish lines and divine avenger.
Right. But in writing a guide, you have to strike a careful balance between precision and conciseness. If you try to be precisely right including all details, then your guide becomes overly long, and no one reads it. If you try to be too short, then you oversimplify things, and no one learns anything. To give you an idea of what I mean: Suppose that you had to pick a heat level that roughly works for all swords, with no disclaimers. What would you pick?
Thanks for your continuing data, by the way. It takes a lot of work, and Three Rings can change it at any time. So it's a frustrating job, but your fellow players really do appreciate it.

Great data, thanks!
Keep in mind that to get to level 5 on a single item costs you 75 radiant fire shards. At a healthy average of 12-16 shards per level, it'd take 75/14 which is about 5 runs, to heat a single weapon to level 5.
As a new 5*, thats around 15 runs to the core if I'm upgrading 3 weapons to level 5, or 45 runs to the core if I'm upgrading 2 armor sets along with it to level 5.
I'd recommend only doing the weapons, until you find armor that you like and want to keep. Also known as chaos set.
----
Also keep in mind that as malignant points out, level 5 won't exactly beat level 10 on the 4* in most cases.

Just checking: Depth 23 is more like Stratum 6 than Stratum 5, right? Because comparing Combuster to Blazebrand on Stratum 5 would not be "fair".
Edit: You should probably ignore this post. Unheated Blitz Needle at depth 28 fares only a little better than unheated Combuster at depth 23.

I think these are some general guidelines.
- 5* weapons are better in tier 1 and 2.
5* weapons at level 8 do less base damage at depths 19 - 26. They do more at depth 27 and 28. #1
5* weapons at level 9 do less base damage at depths 19 - 23 #2. They do more at depths 24- 28. #1
5* weapons at level 10 do more base damage at every depth.
Some 5* weapons gain more than others like better charges and more ricochets which make them favor better
#1. Acheron is an exception and will need less levels to achieve this effectiveness due to buffed base damage)
#2 Depth 23 is basil or punching bags and not really relevant except if there is a mission that has that level
Sword specific:
You could try listing specific exceptions and what level you think they should be (and maybe why). It is less concise but should be more helpful.
I am unsure about acheron but at least level 6 or 7 and lean towards 7).
I recommend the rest of the brandish line heated to at least level 7 and lean towards 8 (except obsidian blade, if you really want to gain poison on the charge).
Level 9 upgrade (maybe level 8 if you do lots of tier 1 and 2 but they are easier tiers):
- Every sword except divine avenger (only when using the charge since you fire 3 projectiles instead of 1 so not sure when to recommend).
and possibly the troika line (gains statuses but probably not worth to upgrade before now)
Edit: Keep in mind that these are minimum levels recommended to not suck and not necessarily be better.

After thinking about how few swords have a qualitative improvement from 4 to 5 stars, I do agree that heat level 5 is an underestimate. So I've added half a sentence about heat level 8. Thanks for your input.

Level 9 is the break even point of tier 3 base damage since strata 5 will do less and strata 6 will do more. Level 8 is the break even point for base damage in FSC since the first two depths will do less and the last two more. This doesn't consider extras the weapon might gain by going 5* like better charges, increased range, or more ricochets nor does it consider the missing ctr low. It really isn't worth it for most weapons without extras unless you can get it to level 10 (Edit: This last sentence doesn't consider tier 1 and 2 effectiveness.).
P.S. I probably won't have time to run FSC and collect the level 10 data for at least a few days.

You might not be talking specifically to me anymore, but in case you are: I'm focused on Stratum 6. Stratum 5 is designed for 4-star equipment anyway.
Please do keep the data coming. :)

My general guidelines rely on a lot of assumptions.
Depth 23 doesn't behave as strata 6 so I guessed that it is the end of strata 5 (or at least behaves like it is in between). I recorded the data of depth 23 and made a leap that strata 5 handled the weird damage calculations the same way as strata 6 (improving better at the highest depth and working back). I also have to make a leap that other 5* weapons (that are not buffed like acheron) have their base damage behave like blitz with only the combuster punching bag data to back it up. I really didn't have the patience to record depths 19-22.
The last post was mostly directed at your comment about level 8 being the break even point, Bopp. I definitely agree that strata 6 is more important than strata 5.

I've updated the old posts with the level 10 blitz data for depths 24-28. The radiant change and the fact that I am no longer really busy motivated me to go through FSC. I got 6 radiants before Vana where before I might extremely rarely get 3 on depth 27. 3 were on depth 25 (I think but I haven't seen people say they got any below depth 26) and 3 were depth on 27.
I recorded the first couple floors awhile after my other post and then had a friend join me so I didn't bother trying to record the data. I did a few more runs with other people during the gap in posts but also never recorded.

I would still have to recommend not upgrading gear to people.
Or at least until they can afford to heat it.. as this is still such a huge limiting factor that the time gear spends is more limited by radiants than anything else.

For anyone that is serious about grinding crowns in vana, I would highly recommend taking the time to make at least level 7 weapons.
-Now that radiants appear more than in what was effectively just D28, the grind is not nearly as bad as it may have once been.
-The number of crystals needed to forge only dramatically increases from level 7 to 8, so until that point you only need anywhere from 110 to 165 crystals.

With blitz, you don't gain extra damage even against Vana until level 8. Elemental brandishes are debatable, but I still recommend at least level 8 especially if it is glacius or voltedge since it less likely to have the extra charge hit.

I realize that, but all I'm saying is that the jump from 7 to 8 is rather high, not that people shouldn't heat. I think that anyone can and should get their weapons to level 10, and its even easier now that you get so many more per run.
Don't upgrade to blitz until you can heat it to at least level 8 where it will finally begin to do better damage at depth 27 (but worse before it so you might have problems one shotting trojans). The wiki says that blitz fires slightly faster so that's something else to consider. I recommend leveling it when you can heat it to level 9 since it will do more damage at
Strike needle at medium damage bonus isn't good enough to one shot trojans in a full elite party (at least, not on every depth). I know very high can do so at every depth. High might be able to one shot them, but I haven't tested it.
The trend continues with 5* weapons at level 9 still having worse base damage on depth 23 (and likely 19 - 23) than 4* weapons at level 10.
vs piercing weak enemies - Tier 3 (depth 23) punching bag
normal, charge
Strike Needle level 10 (no bonus)
106 223
Strike Needle level 10 (high bonus)
126 257
Strike Needle level 10 (VH bonus)
133 268
Strike Needle level 10 (max bonus)
146 291
Blitz Needle level 1 (no bonus)
75 171
Blitz Needle level 1 (max bonus)
108 226
Blitz Needle level 6 (no bonus)
89 194
Blitz Needle level 6 (VH bonus)
113 235
Blitz Needle level 6 (max bonus)
125 255
Blitz Needle level 7 (no bonus)
94 202
Blitz Needle level 7 (VH bonus)
119 244
Blitz Needle level 7 (max bonus)
131 265
Blitz Needle level 8 (no bonus)
99 210
Blitz Needle level 8 (VH bonus)
124 254
Blitz Needle level 8 (max bonus)
137 275
Blitz Needle level 9 (no bonus)
104 219
Blitz Needle level 9 (VH bonus)
130 264
Blitz Needle level 9 (max bonus)
144 287
Blitz Needle level 10 (no bonus)
110 229
Blitz Needle level 10 (VH bonus)
137 275
Blitz Needle level 10 (max bonus)
150 298