Primordial Rune and Radiant Rune are two secret runes exclusive to Infinite Tower mode in Sailor Piece. These runes provide massive stat boosts that make them essential for endgame builds. Here's how to get Primordial Rune and Radiant Rune in Sailor Piece.

How to Get Primordial Rune and Radiant Rune

Both Primordial Rune and Radiant Rune drop exclusively from Infinite Tower mode at Tower Island. You cannot get these runes from bosses, quests, or any other source in Sailor Piece. The tower is the only location where they appear.

  • Primordial Rune Stats: Primordial Rune provides a 112% damage boost when equipped.
  • Radiant Rune Stats: Radiant Rune gives a 26% luck increase. Higher luck improves drop rates for rare items throughout the game.

Both runes are random drops from completing Infinite Tower floors. You'll need to complete many tower runs before getting both runes.

How to Enter Infinite Tower Mode

Infinite Tower requires Tower Keys to enter. You can't just walk into the tower - every run costs one Tower Key. Tower Keys drop from defeating any mobs in Lawless Island. The drop chance is decent, so you don't need to farm for hours to get keys. Just fight regular enemies anywhere in the game, and keys will drop randomly. Farm multiple Tower Keys before starting tower runs. Don't stop at one key - collect a stack of them so you can run the tower repeatedly without stopping to farm more keys between runs. For further details on Infinite Tower Mode, check out our complete guide.

Are These Runes Worth Farming?

Yes, both runes are absolutely worth the grind. Primordial Rune's damage boost is one of the strongest offensive buffs in the entire game, making it essential for anyone serious about endgame content or boss farming. Radiant Rune's luck increase pays for itself over time by improving drop rates everywhere, meaning you'll get better rewards from every boss and mob you farm.

Since Infinite Tower also rewards Tower Tokens, the Abyssal Outfit, Abyssal Empress Sword, and other valuable items, you're not just farming for the runes - you're getting multiple high-tier rewards per run. The time investment is significant, but these runes become permanent power boosts that improve every aspect of your gameplay. For more Sailor Piece guides check out our Sailor Piece Wiki.