Well part of the other reason I put some into energy is because Kalaxia is the final boss of area 6...I'm working on the fourth boss of area 4 right now and progress gets slower and slower, if you have nothing in energy you might hit 10 BSI before being able to reach kalaxia. There are multiple paths to choose though, having equipment which pumps your stamina/energy helps a ton, and perception is giving me good stuff also (Though I put nothing into it, my gear pumps it up A LOT, found two brown skill books last night for an extra ten points, I'm getting stat points like crazy now).