Just got the TRUE ending - pretty good game all around.
I used the nasty combo of Rage + Stillness to cheese the bosses.
What is Rage + Stillness?
- Make character with Dark Knight / Merchant with at least Low Leverage and Rage unlocked.
- Make character with Spiritmaster with at least Stillness unlocked.
- Make sure to slap Agility on Dark Knight so they go before Spiritmaster (important!).
- Having a BP Battery is a good idea. I used Hasten World. This has nasty side effects of putting bosses on a cheese loop themselves, but Stillness counteracts all of it.
- Get a Blood Sword from one of the few areas (Vampire Castle is the earliest spot).
- Have Dark Knight use Blood Sword, for drain effect on sword. Equip a Katana afterward.
- Use Low Leverage to drop the cost of Rage and Stillness to 1BP.
- When you build up a nice amount of BP, try and buff/debuff as necessary (Pay to Play ups critical to 400%).
- Rage Rage Rage Rage, and watch as your Dark Knight does up to 20 attacks in a single turn, without losing health.
- Stillness will be cast afterward, nullifying... everything (except instant death or status effects).
- Repeat, as necessary.