Master Pug will use WallChange every 15 global battle timer intervals, then use an attack linked to its weakness. However, after fighting Master Pug a few times to verify behavior, I've noticed that there is somewhat of a delay. From the (possible) document:
There is a footnote though: there is somewhat of a delayed reaction. After the
WallChange, Master Pug's elemental reaction appears to immediately kick in.
However, Master Pug is somewhat slow to adapt on the offense; for a small moment,
it will still work with the elemental properties from before the WallChange.
In Master Pug's turn comes up during this small period, it'll display 'wrong'
behavior and will either inflict a physical strike (after the very first
WallChange) or perform an attack linked to the previously owned weakness.
Also, Master Pug will take a stop towards the party every WallChange, and execute the following AI script (copy/paste from Lord J:)
(WallChange and step)
1 added to VAR003
If variable VAR003 is greater than or equal to 7
Set VAR003 to 0
Targetting: random ally
This would indicate that after 7 WallChange attacks, he'll use !Cleaver and retreat again. In practive, however, I've consistently counted 8 WallChange attacks. After messing a bit, I've noticed that the FC 0D command that Lord J translates with 'greater than or equal to' functions like 'greater than'. In this instance anyway. Both bover and myself have taken this information for gospel, but this is clearly not the case.
During the FlameEater battle, the FC 0D command does appear to work as an "equal to". More testing is obviously required.
Areneid will check Terra's level; if it's sitting at 7 or higher, it will include !Numb in its AI script. They will also exclusively focus on Terra, though. Lord J's wording doesn't imply that they should, nor do I think that they should. My theory is that they'll mistakingly remember Terra as a target. Also note that Lord J includes the fact that if Terra isn't present any random character's level can be checked; without Terra though, they'll never use !Numb. M-TekArmor:
There's a script in the M-TekArmor bit that counters any Magic spell that strikes an M-TekArmor to cause the M-M-M-Magic cutscene (but only one time). However, starting the first battle with M-TekArmors, this scene will play in any battle (Leaver, Bleary, Hornet, what have you) and it's triggered by any casting of Magic, be it offensive or curative (though the cutscene leans towards Terra performing some destructive act). So this is just a bit of useless AI script...?