Malboros themselves, fought in the Calm Lands, are not hugely threatening. You need to hit them till a hidden counter reaches seven before they use Bad Breath, by which time they'll likely be dead. Great Malboros, on the other hand, are deadly. If encountered in the final dungeon before the point of no return, they do not have a 100% chance of an ambush, but everywhere else (Omega Ruins, final dungeon after point of no return) they do, even if you have Initiative equipped. They will always use Bad Breath on their first turn when they ambush. So if you encounter one without First Strike equipped, you're in big trouble.
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Praise the Black Turtle, Game of the Decade Guru Champ.
(Well, I never promised creativity, did I?!)