Very nicely done game
I played this until I finished it. Which meant discovering that the experience/level-up system was similar to Final Fantasy VIII's, and the painful truth of having to restart because I was too powerful, and thus, my enemies were too powerful (No Lion Heart/Aura Stone combo to save me in this game). Your tips are kinda mean to the average player, in a good kind of way, but if a player ever reaches battle level 7 with 17's in each attribute with every technique, they will not ever succeed against the final boss, and popping 22k for the next upgrade in any field isn't my idea of a good time.
For you new guys out there: Vitality is BAD. VEEEERY bad. It boosts the life of your enemies, and it makes everything take longer to kill, including bosses. Raising your battle level once is fine. Increasing it past that point can heavily complicate things for you, since that levels up all the enemies in all of their statistical fields. When you begin the game, crank your encounter rate to maximum, and focus on getting the Haunted technique. Next, focus strictly on Strength and Magic, since the two influence the strength of all learned techniques. Boost your battle level once, and then focus on mana until you have exactly 200. after this point, focus on saving up for the ultimate attack.
I was able to 1-Hit kill pops in the last battle doing this... well, that's where the weird part comes in. I saved my data to the fifth file, and my save got screwy, shooting me from Act I to Act III. Now, I have my storage capacity for my flash to unlimited, so I don't know what happened. I saved the jumped data, and reloaded the original file, and found the save to be completely screwed. You might want to check your file save code for errors on this one. It's not pertinent, really, but just know that the fifth save is all bugged up.
Again, suave game, I enjoyed it a lot and keep up the good work.