Much like any other NIS game.. if you tough it out and get to the point where you can really take advantage of the stacking multiplier effects, you become unstoppable. It would take an incredible amount of time to get through this game the hard way, but the game gives all sorts of outlandish ways to cheat your way to the top. Right now, I'm running a magic circle that has my Lv. 32 Wizard running with 354 SP, with a Mana Debt capability of 534 SP. Then I've got a 100% level boost on my Fire Storm.
What that means is by using a single spell, I can one-shot a boss that's 30 levels higher than me. And all I have to do is wait for a countdown to get down to zero, and I can do it again.. as often as I want.