That would at least be an appropriate word for a mode higher in difficulty than "Expert", heh.
As the difficulty goes, I should go further yet before I try to judge it much. I did get a good challenge out of the one assassination mission that I've done so far, that was fun. It's been very enjoyable overall, too.
One thing that does occur to me is that, at least for the higher difficulties, having some of the "rare" bots appear more often might be an interesting way to add to the challenge without just altering stats more. Like, I'll often do a mission, and I'll encounter something like, I dunno, a WyvernBot or whatever, but I'll only encounter 2 or 3 of it in said mission, while I'll run into like 50 of everything else. The idea of having something particularly dangerous appearing in a mission, but only a few of it, is a good idea, but it might be TOO few to have much impact. Maybe even have an occaisional boss appear unexpectedly in a mission, and not necessarily one of the two chosen types for the final army. It'd be kinda neat to see those types have more of a presence in the game, as they make for interesting fights.
So far, the various "buff" bots seem to be the ones that add to the challenge the most. The interesting thing with those guys though is what happens if you virus them.... but that can be really darned risky depending on the situation since it often means letting those things live longer and buff more enemy bots.
I wonder, is anyone else playing this mode, that might have some extra feedback on it? Admittedly my ideas of what a "challenge" is defined as can be a little warped, so other opinions on this mode might be helpful.
EDIT: It's also worth noting that I'm like 18 or so days into the game at this point, and still havent found even one of the Bahamut upgrades.... unlike my earlier games, where they would sometimes show up really close to the starting point. Those can definitely alter the challenge level a bit. Particularly if gotten early.