GBW3 damage coding

Note: this is for Red Star's side of things. White Moon's uses similar enough values.

0C:4A26 FAD7DB  ld a,[$DBD7]
0C:4A29 47      ld b,a - B carries Level byte
0C:4A2A FAD8DB  ld a,[$DBD8]
0C:4A2D 4F      ld c,a - C carries Flank byte
0C:4A2E FAD9DB  ld a,[$DBD9] - A carries Support byte
0C:4A31 CDA249  call $49A2 - H is the truncation of the multiplier, L is the float point (percent being value multiplied by 64/25)
0C:4A34 54      ld d,h
0C:4A35 5D      ld e,l - D is the truncation of the multiplier, E is the float point (percent being value multiplied by 64/25)
0C:4A36 FAD4DB  ld a,[$DBD4]
0C:4A39 47      ld b,a - B carries ATK byte
0C:4A3A FAD3DB  ld a,[$DBD3] - A carries HP byte
0C:4A3D CDFC49  call $49FC - Total ATK = ATK * HP * (100 + ATK boosts) / 100; Float error causes slightly lower values on any number not a multiple of 25
0C:4A40 7D      ld a,l
0C:4A41 EADADB  ld [$DBDA],a
0C:4A44 7C      ld a,h
0C:4A45 EADBDB  ld [$DBDB],a - $DBDA (2 bytes) carries Total ATK
0C:4A48 E5      push hl
0C:4A49 216400  ld hl,$0064
0C:4A4C FAECDB  ld a,[$DBEC]
0C:4A4F 47      ld b,a - B carries opponent's Level byte
0C:4A50 FAEDDB  ld a,[$DBED]
0C:4A53 4F      ld c,a - C carries opponent's Flank byte
0C:4A54 FAEBDB  ld a,[$DBEB] - A carries opponent's Cover byte
0C:4A57 CDCC49  call $49CC - H is the truncation of the multiplier, L is the float point (percent being value multiplied by 64/25). All 3 multiplier change bytes have half effect, if you're wondering.
0C:4A5A 54      ld d,h
0C:4A5B 5D      ld e,l - D is the truncation of the multiplier, E is the float point (percent being value multiplied by 64/25)
0C:4A5C FAEADB  ld a,[$DBEA]
0C:4A5F 47      ld b,a - B carries opponent's DEF byte
0C:4A60 FAE8DB  ld a,[$DBE8] - A carries opponent's HP byte
0C:4A63 CD214A  call $4A21 - for opponent, Total DEF = DEF * 2 * HP * (100 + DEF boosts / 2) / 100; Float error causes slightly lower values on any number not a multiple of 25
0C:4A66 7D      ld a,l
0C:4A67 EAF1DB  ld [$DBF1],a
0C:4A6A 7C      ld a,h
0C:4A6B EAF2DB  ld [$DBF2],a - $DBF2 (2 bytes) carries opponent's Total DEF
0C:4A6E D1      pop de - if you're confused, at this point, the Total ATK would be at the very top of the stack from the Push HL instruction, so DE would be holding the Total ATK value now
0C:4A6F CDC329  call $29C3 - HL = Total DEF - Total ATK
0C:4A72 3822    jr c,$30A96 - if HL is now negative, this basically sets A to 0 and ends the whole thing. The opponent's unit will be destroyed as a result.
0C:4A74 54      ld d,h
0C:4A75 5D      ld e,l
0C:4A76 FAEADB  ld a,[$DBEA]
0C:4A79 07      rlca
0C:4A7A 4F      ld c,a - C is double the opponent's DEF byte
0C:4A7B 0600    ld b,$00
0C:4A7D CD212A  call $2A21 - DE = (Total DEF - Total ATK) / (DEF*2); BC holds remainder
0C:4A80 78      ld a,b
0C:4A81 B1      or c
0C:4A82 2801    jr z,$30A85
0C:4A84 13      inc de - if remainder != 0, increase DE by 1
0C:4A85 7A      ld a,d
0C:4A86 A7      and a
0C:4A87 2008    jr nz,$30A91 - yeah, why should DE even approach 255?
0C:4A89 FAE8DB  ld a,[$DBE8]
0C:4A8C 57      ld d,a - D carries opponent's HP value
0C:4A8D 7B      ld a,e - A carries expected new HP value
0C:4A8E BA      cp d
0C:4A8F 3806    jr c,$30A97 - if the expected new HP value is lower, this procedure will be ended
0C:4A91 FAE8DB  ld a,[$DBE8] - forces HP to remain unchanged if the new value were to exceed the old one
0C:4A94 1801    jr $30A97 - ends
0C:4A96 AF      xor a
0C:4A97 C9      ret