What Are Rune Swords?
Rune Swords are the demon-forged Oni weapons in Way of the Sword. Each one unlocks a unique skill in the Oni Gauntlet — the second-tier parry cancel, the multi-hit Issen extension, or the soul-siphon passive. They are not class-restricted, but the upgrade tree branches hard at level 4, so choosing which to commit to first shapes your whole build.
Rune Sword stats at a glance
| Sword | Base ATK | Best For | Chapter |
|---|---|---|---|
| Onimaru | 48 | Early parry cancel, beginner build | 2 |
| Kaneshige | 62 | Multi-hit Issen, mid-game DPS | 4 |
| Tachibana Yuki | 55 | Soul-siphon passive, farming | 6 |
| Enryuu | 78 | Late game, stagger break | 9 |
| Bishamon | 91 | Hidden, NG+ viable, true ending req. | 12 (missable) |
Onimaru — Chapter 2, Riverside Shrine
The first Rune Sword is given, not found. After the Riverside Shrine encounter, Samanosuke (or his NG+ alternate) hands you Onimaru in the cutscene. Don't dismiss it as a starter weapon — its parry-cancel talent feeds directly into the best early build path.
Upgrade priority: Onimaru → Onimaru+1 → Onimaru+2 (cost: 1,200 red souls). Stop there until you have a second Rune Sword.
Kaneshige — Chapter 4, Burning Forge Vault
Kaneshige is the reward for clearing the Burning Forge vault. The chest is behind a Sokushi-type Genma that you have to deflect three times in a row — even a single hit will reset the encounter. Bring Tachibana Yuki (yes, you need a third sword to fight a Ch.4 boss — see the chicken-and-egg note below).
Stock 2,400 red souls and at least 3 Oni Gauntlet charges before attempting. The Kaneshige upgrade path to Kaneshige+3 unlocks the multi-hit Issen — the single biggest DPS spike in the mid game.
Tachibana Yuki — Chapter 6, Floating Pagoda
Found at the back of the Floating Pagoda, behind a breakable wall you have to Issen through. Tachibana Yuki's signature is the Soul Siphon passive: every defeated Genma drops 1.5× normal red souls while it is equipped. It is the farming sword. If you intend to max anything to +5, equip Yuki first.
Enryuu — Chapter 9, Mountain Pass Tower
Enryuu sits in a chest on the second-highest tier of the Mountain Pass Tower, but the tower is collapsing on a 90-second timer. You have to skip two mini-bosses to reach the chest in time. The skip is the standard left-rail path through the upper gallery.
Encounter prep: Bring Enryuu (yes, it is technically not yet yours — the chest is the source) and 3 Oni Gauntlet charges. Two of the Genma in the tower are staggered by Enryuu's Level-3 Oni Art, so you can break formation early.
Bishamon — Chapter 12, Hidden Courtyard (Missable)
Bishamon is the only Rune Sword that can be permanently lost. After the Chapter 12 courtyard, you get a 90-second prompt to either fight the Hidden Genma or leave for the boss. Choosing leave skips Bishamon for the rest of the run. There is no NG+ unlock — you have to start a new save.
Always make a separate save before the Chapter 12 courtyard. The Bishamon fight is the hardest Rune Sword duel, and losing the chest loses you the only weapon that meets the true-ending damage threshold in NG.
Which Rune Sword to Upgrade First?
For a first playthrough, the answer is Kaneshige. Its multi-hit Issen carries both PvE and NG+, and the soul cost to +3 is reasonable (~4,800 red souls). Save Bishamon for a dedicated farming run with Tachibana Yuki equipped — you will need roughly 12,000 red souls to fully upgrade it, and most of those will come from the Yuki passive.
Common build paths
- Beginner / first playthrough: Onimaru → Kaneshige → Yuki (skip Enryuu and Bishamon until NG+)
- Soul farming: Yuki main, swap to Enryuu for boss stagger
- NG+ true ending: Bishamon main, Yuki passive in second slot