I didn't ever die against storyline bosses or regular monsters. I did, however, lose to Dark Valefor once (I totally didn't know it was there... very much unprepared), once with Dark Bahamut, and no doubt a couple of times against the Great Malboro in Omega Ruins.
Now that I look back, that's a poor amount for a first play-through. Bosses should be tougher...
Now that I look back, that's a poor amount for a first play-through. Bosses should be tougher...