huh, halving your stats AND clearing the battle in less than 20 seconds? You'd need to be over the level of the enemies, which mean the exp they'd give would drop a lot.
I think it's best to only put the recipe that increases exp after you've spent 1 minute in battle and increase slowly the difficulty so that the enemies are always at a level above yours. This also allows to put a recipe that increases your max HP at the end of the battle instead.
Judas: We'll probably have to find some other way to decide the strongest. For example... Zelos: Like how cute your girlfriend is?