The cheevo? Theoretically, getting levels from weaker east stuff and then building up to take down the end game. It's... conceptually possible. It would involve a lot* of restarts, waiting -- hoping, begging -- that the RNG will give you just enough of a break early on to get your feet underneath you. You'd be (probably vainly) trying to prey on the rare low level critter (such as the aforementioned orc warriors, if you can get them sufficiently alone to get a kill in and survive afterwards.) enough times to slowly, painfully, eek out enough levels to attempt something riskier (and mind you, the risk involved in just that is such that for every attempt that actually works, you will likely die a dozen dog's deaths.), and then basically keep repeating the process until you've ground up enough loot and XP (a prospect that becomes much more palatable if you ever reach the point you can comfortably kill orc patrols. Good luck.) to push on through. If a million and one stars align, your every step defined by the RNG metaphorically fellating your character, and you play like a bronzed grecian god of roguelike gaming, you might be able to pull it off after a few dozen attempts. Mind you, that's not counting all the attempts in which the stars aren't aligned. There'd be a lot more of those.
Alternately. Memory. Freaking. Editor. T4 doesn't recognize that as cheating, so it'd come out looking like a legit character. Freeze your HP at max, give yourself infinite everything useful, and go to town.
*This is a grotesque understatement. I would expect at least several dozen attempts before one even started to get through, and several dozen attempts for each one of those lucky runs before you got even middingly further, and then probably several dozen more for each one of those, just for the privilege of getting completely demolished by the high peaks and endgame fight because you're still under-leveled and under-equipped. Many hundreds, probably thousands, of characters later, you might manage to kill one of the end game bosses. And then die. It is a Sisyphean hell of an achievement.