MA + X

No Parameters 

Returns r2 = 0x00 if Attack hits / 0x01 if Attack misses

Modify XA (Support/Compatibility)
Add XA and YA to becomes Hit% (it is stored in Target Current Action HP damage (0x04))
Modify Hit% with Faith (while sotred in HP damage)
Roll Hit% Vs Random (from 0 to 100)
 - Returns r2 = 0x01 if Attack misses
 - Returns r2 = 0x00 if Attack hits

Note : this is the accuracy formula for friendly spells (no magic defense up mechanics nor status effects on XA)
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00188800: 27bdffe8 addiu r29,r29,-0x0018    |
00188804: afbf0010 sw r31,0x0010(r29)       |
00188808: 0c061881 jal 0x00186204           |-->Magic Attack Up routine Ability XA +33% If Attacker uses Magic Attack Up
0018880c: 00000000 nop                      |
00188810: 0c061259 jal 0x00184964           |-->Compatibility Alters XA (-50% to +50%) based on compatibility
00188814: 00000000 nop                      |
00188818: 0c061967 jal 0x0018659c           |-->Set XA + YA for Status Formulas (Stupid section) XA+YA becomes TCA HP damage (YA is processed via compatibility)
0018881c: 00000000 nop                      |
00188820: 0c061c54 jal 0x00187150           |-->Faith Calculation HP damage becomes Base HP damage * Target faith/100 * Attacker faith/100
00188824: 00000000 nop                      |
00188828: 0c061d44 jal 0x00187510           |-->Uses_HP_damage_as_Action_hit%25 HP damage becomes Hit% - Roll Hit% vs random (0 to 100), Set Action hit flag to miss if it fails
0018882c: 00000000 nop                      |
00188830: 3c028019 lui r2,0x8019            |
00188834: 8c422d90 lw r2,0x2d90(r2)         |r2 Target current action (TCA) data pointer
00188838: 00000000 nop                      |
0018883c: 90420000 lbu r2,0x0000(r2)        |r2 = TCA Hit flag (0x00 if miss, 0x01 if hit)
00188840: 00000000 nop                      |
00188844: 2c420001 sltiu r2,r2,0x0001       |r2 = 0x01 if Hit flag = 0x00 (miss)
00188848: 8fbf0010 lw r31,0x0010(r29)       
0018884c: 27bd0018 addiu r29,r29,0x0018     
00188850: 03e00008 jr r31                   
00188854: 00000000 nop                      

Return locations

00188ed8: Formula 0b : Hit F(MA+X)%
00188f58: Formula 0d : Heal (Y)% Hit F(MA+X)%
00189144: Formula 12 : Set Quick Hit F(MA+X)%