Candy Box – What is Sword Level?

The way I did it seems pretty fool-proof. I just ran in and popped an invulnerability potion right before I touched the boss. Then when it runs out teleport back. When you get to the boss next time, the timer still won't be up though, so you'll have to use another teleport scroll, but then the next time you can turn invincible again, and repeat the strategy until victory. It's pretty costly, but the winnings will pay for it easily.

You can use a Scroll of Fire to enchant a Fire Sword, which does a small amount of additional damage.

You can use a Health Potion to enchant a Life Sword, which awards you some health back on hit.

You can use an Imp Invocation Scroll to enchant a Sword of Summoning, which has a chance when you kill an opponent to summon a friendly minion in it's place, which can act as a meat shield to protect you and kill enemies.

Which you use is primarily a matter of style. The Summoning Sword is clearly better against a number of trash mob types, but it tends to fall flat against bosses or other foes with high HP. The Life Sword offers longevity, but you lose some offensive punch, etc.