So I've been trying my darnedest to figure out new battle addresses and reverse damage equations and such. A long while back I found this structure of data that is used over 1200 times in the exe and is only used during battle. This seems to be populated per-target of an action whenever a battle actor initiates a command. I'd put this on the wiki, but there doesn't seem to be a place for it since the wiki doesn't deal with direct memory.
This is all for the PC's structure, first of all. The actual data is stored at 0x99E308, but there is a constant pointer to that address at 0x99CE0C that is what's always referenced. The next mapped memory address appears to be 0x99F308, but it hardly uses any of that. It consists solely of 32-bit DWords even if the value stored is a single byte. It uses 256 bytes for the actor and technical information of the attack then an additional 100 bytes for target data with a 256 byte gap between them. So the valid ranges look like 0 - 260h for the size of the array. I've mapped out quite a bit of it, but some is still eluding me. I thought I'd share what I have so far. For these purposes, "Actor" is the one performing the action.
000 - Actor Index (0-2 are playable characters, 4-9 are enemies)
004 - Actor Level
008 - Battle Formation Index?
00C - Command Index
010 - Action Index
014 - Action Data Base (0 for magic, 38h for summon, 48h for E.Skill, something else for scene.bin and limit attacks)
018 - Allowed Targets (seems to only select non-dead, active targets)
01C - Active Allies
020 - Actor's Command Animation (animation index for current action)
024 - Action Visual Effect
028 - Command Index again?
02C - Action Index again? (lots of repeats)
038 - MP Cost
03C - Action Accuracy
040 - Damage Calculation
044 - Action Element
048 - Action Power (typically 16, 2 for morph)
04C - Actor Attack or MAttack (depends on what type of attack it is)
050 - Action Targets (bitmask)
054 - Action Impact Sound
058 - Action Impact Sound again?
05C - Action Impact Sound yet again?
060 - Action Single target Camera index
064 - Action Multiple target Camera index
068 - Action Impact Anim Index
06C - Special Attack Flags
070 - Not used?
074 - Not used?
078 - ?
07C - ?
080 - Inflicting Statuses
084 - Curing Statuses
088 - Toggle Statuses (these are only ones the Action is told to effect, not the ones that actually connect and inflict)
08C - Chance to Affect Statuses
090 - Command Properties (4h - Steal attempt; 2000h - Morph attempt; etc)
094 - Some other flags?
098 - Action Index position in scene
09C - ?
0A0 - Accuracy check function (upper nybble of damage calculation value)
0A4 - Action Damage Function (lower nybble of damage calculation value)
0A8 - ?
0AC - related to magic effects, but I'm not sure what
0B0 - Number of damage calculations?
0B4 - ?
0B8 - number of targets?
0BC - Action Additional Effects
0C0 - Action Additional Effect Magnitude
0C4 - Action Power (copy of 48 above)
0C8 - Actor's current statuses
0CC - Target's Action connect animation
0D0 - ?
0D4 - ? (these two are related somehow
0D8 - Actor's Strength
0DC - Some battle related flags (36h indicates successful escape)
0E0 - ?
0E4 - ?
0E8 - ?
0EC - ?
0F0 - AllowedMagic (I don't know what that means)
0F4 - ?
0F8 - AllowedMagic (might be allowed multiple toggles)
0FC - ?
<these get changed per target>
200 - ??
204 - Character Map address (playable chars only)
208 - Target Index
20C - Formation Slot (enemy only)
210 - Target Def/MagDefense
214 - Damage taken from Action
218 - lots of flags (1h - successful hit; 4h - steal attempt; 20h - some always hit check?; 4000h - Barrier active; 8000h - MBarrier active)
21C - ?
220 - Some flags (1h - damage is healed; 2h - Critical Hit; 4h - Damages MP)
224 - Target Reaction Animation (copied from CC above I think)
228 - Target's current statuses
22C - Target's status immunities
230 - Some other weird flags (1h and 80h are used by the "Recover" damage calculation)
234 - more flags (1h - back exposed; 2h - multiple targets?)
238 - Status related (statuses successfully inflicts?)
23C - Action removes these statuses from target
240 - Status related also (statuses toggled?)
244 - ?
248 - Sound to play
24C - Action Animation to use
250 - ?
254 - Target's Level
258 - Target's HP
25C - Target's MP
260 - Action Accuracy
That's all I got. If anyone has any more info on this I'd like to know.