Icebore

Icebore gives arrows +1 damage against frozen Bloons, and whenever the Skywarden pops a frozen Bloon, all its projectiles gain 50% more pierce for 1 second (popping more frozen Bloons during the buff does not extend it). Higher tiers raise the frozen bonus: +2 on Galesage, +4 on Galvanic Conduit and Thunder's Decree, +5 on Farwind Seer and +10 on Stormwrath Archon.

When to buy it

• It is strong next to freezing towers such as Snowstorm, Icicles or Silas, which create a steady stream of frozen targets.
• Without freezing support, it does almost nothing, and Skywardens alone (Coldchain or higher) freeze fewer Bloons than dedicated ice towers.
• It is the required step to Coldchain and the rest of the ice path.

Is it worth it?

Yes in an ice-based defense. Otherwise, stop at Shatterpoint for the pierce and spend the rest elsewhere.