Best Quill Volley Spiritborn Runewords
Runeword 1: PocQue

Required Runes: Poc and Que Legendary Runes
Socket Placement: Head slots (instead of Gems)
Effect:
Resource Management: Spends 5% Resources to Diablo 4 Items generate 5 Offering (Overflow generates more). At 300 Offering, the Druid's Earthen Bulwark is cast for free.
Utility: This runeword provides you with extra defense and resource generation, essential for sustainability. As a Quill Volley Spiritborn, the ability to generate Offering and trigger the Earthen Bulwark makes you tankier and extends your uptime in fights.
Runeword 2: CirGar

Required Runes: Cir and Gar Legendary Runes
Socket Placement: Pants slots (instead of Gems)
Effect:
Crit Chance Boost: After casting the same skill 3 times in a row, Crit Chance is increased, which is ideal for this build that focuses on cheap Diablo IV Items rapid casting and high mobility.
Why It's Good for Quill Volley: Since Quill Volley is frequently cast, this runeword increases your Crit Chance, amplifying your damage potential, especially when paired with gear that boosts Crit Damage and Vigor regeneration.