Piranha battle

I don't really know much about the special event data. It looks like it's at $D0FD00 and they're 18 bytes each. Does anyone know how this works?

For the FB 0D 00 command, I looked up the code that gets called. All it does is set "hide" status for that monster.

Code:

C2/1F00: B9 F9 3E     LDA $3EF9,Y
C2/1F03: 09 20        ORA #$20
C2/1F05: 99 F9 3E     STA $3EF9,Y     ; set hide status
C2/1F08: 60           RTS

There's one other unique thing about the piranha battle. There's a bit in their monster data that sets bit 7 at $3E4C ($3E54 for monsters). In FF3ME, it's called "Removable Float", but I think that's incorrect. I call it "piranha" status.

Here's what that bit really does: At the end of each turn in battle, the game checks which monsters just died. Any monsters with "hide" status become dead. Monsters with pending counterattacks don't become dead, *unless* they have "piranha" status. That way, the piranha will always die before the new piranhas spawn. There's definitely some redundancy there, but I did a test to see what would happen if I disabled this code *and* got rid of the FB 0D 00 commands in the AI script. Here's a video of what happened https://youtu.be/nVBEQ0grayc. And here's the code:

Code:

C2/1429: A2 0A        LDX #$0A
C2/142B: BD 21 30     LDA $3021,X     ; monster mask
C2/142E: 2C 3A 3A     BIT $3A3A
C2/1431: F0 17        BEQ $144A       ; skip if monster is still alive
C2/1433: EB           XBA
C2/1434: BD 01 3F     LDA $3F01,X     ; status 4
C2/1437: 89 20        BIT #$20
C2/1439: D0 0B        BNE $1446       ; mark monster as dead if it has hide status
C2/143B: BD 54 3E     LDA $3E54,X
C2/143E: 30 06        BMI $1446       ; skip if piranha status
C2/1440: BD D5 32     LDA $32D5,X     ; pointer to next pending counterattack
C2/1443: 1A           INC
C2/1444: D0 04        BNE $144A       ; branch if there is a counterattack pending
C2/1446: EB           XBA
C2/1447: 1C 2F 2F     TRB $2F2F       ; mark monster as dead
C2/144A: CA           DEX
C2/144B: CA           DEX
C2/144C: 10 DD        BPL $142B
C2/144E: 60           RTS