This is covering the process that needs to be completed to fully upgrade the broken hero sword. From experience, it is possible to complete using these steps on almost every run, so long as the materials for the sword are prioritized.
Guide to Hero Sword
- Broken Hero Sword (starting item)
- 120 Gold
- Blacksmith Whetstone
- Flex Material
Broken Hero Sword
Choose the Broken Hero Sword as the starting weapon before starting the run. If you’re going for a melee build, this is by far the best weapon to invest in and doesn’t fully depend on good RNG.
Hint: Don’t bother enchanting the broken hero sword or hero sword, the enchantment resets when the sword evolves.
Collect Gold as fast as possible. You need to get to 60 gold as soon as you can, so that you are ready for the blacksmith when he appears. If you see a blacksmith early on, you can go ahead and upgrade the broken hero sword to +2, but you need the Mythril before going to +3.
At boss rooms, choose Mythril as soon as you see it. This can appear as soon as early as the first boss, but usually shows up within the first two to three floors.
Once you have both Mythril and enough gold to get your broken hero sword to +3, upgrade at a blacksmith to get a Hero Sword. The Hero Sword is decent enough to use as a weapon if your current one sucks, but we want the final version. If you have extra gold, you can go ahead and upgrade the Hero Sword further, up to +3.
Hint: If you run into a rare or uncommon weapon and then a tavern with the Knight, picking up the free whetstone early can help later. Don’t use the whetstone for these early stage weapon upgrades, since it is one of the few ways you can upgrade to +4.
Your flex material can now spawn as early as the next boss room, and just like before, you want to grab that as soon as possible. The -flex material can be various elementals (all of the ones I’ve used are great), but won’t spawn until you have the Hero Sword in your inventory. The different options are: Heatflex (fire and inflicts burn), Voltflex (lighting and inflicts shock), Iceflex (Ice and inflicts Chill), Toxiflex (toxic and inflicts poison) or Darkflex. Each version varies slightly, but usually fires multiple shots per swing in a wide arc.
At this point, the Hero Sword is good enough quality for the knight at the tavern to give you a whetstone. In order to upgrade to the final version of the Hero Sword, you need to get it to +4 while having the -flex material in your inventory. Whetstones are the easiest way to upgrade to +4 for melee weapons, and the knight gives you one for free, provided you can show him a sufficiently rare equipped weapon. I suggest grabbing the whetstone whenever you can, but there’s no need to visit the tavern if you don’t have a rare weapon to show the knight.
Enjoy your masterwork sword. The fully upgraded sword scales with all attributes at level A or higher (depends on the elemental you get), so even if your build went a different direction, this should be a decent upgrade from most weapons you might find otherwise. If you have the gold, the sword can still be upgraded further with another whetstone, at a blacksmith, or if you manage to find the mythril forge on lower floors. The perk “Nature’s Wrath” works well with it, for an intelligence/Hero Sword combo.
You are also able to enchant your new weapon to further increase its stats.