21 DmgMP (MA*Y)

[21]
001895f4: 27bdffe8 addiu r29,r29,0xffe8     |
001895f8: afbf0010 sw r31,0x0010(r29)       |
001895fc: 0c061e44 jal 0x00187910           |-->Katana Break Chance  Roll Break chances (Wepon Power%), update Attacker current action special flags
00189600: 00000000 nop                      |
00189604: 0c061725 jal 0x00185c94           |-->Store MA and Y XA = Attacker's MA and YA = used Ability Y
00189608: 00000000 nop                      |
0018960c: 0c0621d1 jal 0x00188744           |-->Magical Support/Status/Compat Modify Ability XA (Support Abilities, Status, Compatibility)
00189610: 00000000 nop                      |
00189614: 3c038019 lui r3,0x8019            |
00189618: 946338ce lhu r3,0x38ce(r3)        |r3 = Current Ability XA
0018961c: 3c028019 lui r2,0x8019            |
00189620: 944238d0 lhu r2,0x38d0(r2)        |r2 = Current Ability YA
00189624: 00000000 nop                      |
00189628: 00620018 mult r3,r2               |XA*YA
0018962c: 3c038019 lui r3,0x8019            |
00189630: 8c632d90 lw r3,0x2d90(r3)         |r3 = Target Current Action (TCA) data pointer
00189634: 34020020 ori r2,r0,0x0020         |r2 = 0x20 (MP damage Attack type flag)
00189638: a0620025 sb r2,0x0025(r3)         |Set TCA Attack type to MP damage  (disables others flags)
0018963c: 00001012 mflo r2                  |r2 = XA*YA
00189640: a4620008 sh r2,0x0008(r3)         |Set TCA MP damage = XA*YA
00189644: 8fbf0010 lw r31,0x0010(r29)       
00189648: 27bd0018 addiu r29,r29,0x0018     
0018964c: 03e00008 jr r31                   
00189650: 00000000 nop

Return location

Battle.bin
0018b97c - Pre Formula Setup