I couldn't really see a difference between a regular sword and the energy sword but I built up the energy sword anyway. Also, make sure to build up luck, drohne, Luck is the modifier that gives you better drops (money and jewels) and rarer monster encounters (which equals more money).
This game has so many rare monsters that drop lots of money. I recently fought a armor monster called "Apocalypse". So awesome.
Also, I beat the Hellhound Boss. You have to 1) Get the 100,000,000 Gold Chaser Spell 2) Build up your Intelligence to atleast 250 so its effective and 3) Make your sword its minimum size so the Hellounds main attack isn't as large (his main attack is based off when you click. Its best to stick to the upper and lower corners of the Boss). You get a special item that's used on the first map. The battle is still kind of tough with those prerequisites. You still have to dodge the little red dot missiles, 3 alone will kill me