Well, I just assumed two things:
1) Players would be using their magic instead of just mashing attack.
2) I assumed that players would assume that a dragon using fire attacks would be weak against water/ice type attacks. I guess it's a Pokemon mindset or something.
But yeah, since four people have said that it's too hard without an explanation of the weakness, I guess it needs one, so definitely feel free to add it. Sorry about that guys.
-edit-
Oh yeah.
Okay this is weird. On the 16th attempt the monster didn't even attack at all. Has Impeal/Mateui got an explanation for this?
That never happened to me, but I only tested it 4 or 5 times. I have no idea what could cause it, since the battle doesn't have any battle events, and the bahavior settings all seem correct. =\
-edit again-
That happened to me too as well. On my first go at that boss, he didn't even attack at all for some reason. Later, I tried to do it again, but kept of losing, as I was always running out of defibrillators, and Savis kept of being KOed. Eventually I won, by pressing attack over and over.
Well, if memory serves, you shouldn't even have any defibrillators at that point in time, since Fighter's chapter didn't have any and the boss is literally a minute or two into my chapter. But, the way I planned it out, if you fight the battle right, you shouldn't need any defibrillators. If Savis kept on being KO'd, then that's really just bad luck and means that the boss was getting high hits in.
The boss doesn't use his strong attack (fire breath) until 4 moves into the battle. Savis should survive one or two of his normal hits, which means she should be able to get in one or two attacks before dying of a normal hit (and this is assuming that the boss doesn't attack Aydin instead). The ice attack will always freeze, so just one turn should be more than enough to freeze the monster.
The only way I could see someone losing the battle is if they either didn't use magic or just got exceedingly unlucky. There is more than enough time to freeze the monster, at which point it's frozen for the rest of the battle and you can just chip away at it's health while it stands there doing nothing.
In fact, now that I say that, that could possibly be the explanation of why the monster didn't attack you guys in certain battles. If you used your ice magic before it got the chance to do a first attack (which is likely, since its agillity is lower than Savis') then it would be frozen for the rest of the battle and not do anything, so it would give the impression that it doesn't attack. In fact, I'm now pretty sure that this is what happened. Once it's frozen, when you target it with an attack, it should say "Paralyze" in blue letters at the top of the screen. That's how you can tell if it's frozen or not.
But yeah, if the battle pans our correctly, you shouldn't have to use any items and you should take minimal if any damage. But that's only if you paralyze the boss. If not, you'll definitely have a tough time.