The Vault is a late-game upgrade system that appears on your home screen once you are promoted into the Legends League. It contains two tech trees of permanent upgrades: Power, which covers tower-related buffs, and Harmony, which covers non-tower buffs and quality-of-life improvements.
Every upgrade in The Vault is bought with Keys, a currency you can only earn through your placements in the Legends League. If you want to progress these trees, consistent Legends participation is the only route.
The Vault
Each tree starts at the bottom and grows upward. You buy the first unlocks at the base, then branch out along the paths shown by the small white arrows in the tree images to reach further upgrades.
The Power tree adds a tier system on top of this. Most nodes can be upgraded to Tier 2 and Tier 3, with each tier costing more Keys: Tier 2 costs double the Tier 1 price, and Tier 3 costs quadruple it. Tiers are gated by your total unlocks. Tier 2 becomes available once you have 15 Tier 1 unlocks, and Tier 3 requires 30 Tier 1 unlocks plus 15 Tier 2 unlocks.
A handful of Power upgrades have only a single level and cannot be tiered up: Ultimate Weapon Damage (All), Bot Range (All), Wall Rebuild, Shockwave Frequency, and Orbs.
Harmony Tree
The Harmony tree holds the non-tower side of The Vault: buffs that do not affect your tower directly, along with quality-of-life upgrades. It follows the same structure as the rest of The Vault, with upgrades purchased using Keys earned from Legends League placements and later nodes opening up as you unlock the ones below them.
The table below lists the Harmony upgrades and their effects.
| Upgrade | Description | Extra notes |
|---|---|---|
| Demon Mode Automation | Demon mode will activate when it's cooldown is complete. | Can be disabled by clicking the Demon Mod card |
| Smart Demon Mode Automation | Demon mode will activate to save the tower from a killing blow. | This only works if Demon Mode is available when the Killing blow is encountered. The order of priority for killing blows is Death Defy > Energy Shield > Second Wind > Smart Demon Mode > Smart Nuke. |
| Free Mission Reroll | Unlimited free mission rerolls | |
| Nuke Automation | Nuke will activate when it's cooled down is complete. | Can be disabled by clicking the Nuke card |
| Smart Nuke Automation | Nuke will activate to save the tower from a killing blow. | Nuke does not destroy projectiles already in transit, so this may not prolong a death if a killing projectile is already traveling to the tower but as of v27.3 (18 Dec, 2025) Smart Nuke provides 15 seconds of invulnerability. The order of priority for killing blows is Death Defy > Energy Shield > Second Wind > Smart Demon Mode > Smart Nuke. |
| Workshop Presets | +5 workshop presets | The Presets retain how much coin is invested in Workshop and workshop enhancements and allows to you swap to a different distribution that you invest in. |
| Ad Gem Stack | Ad gems can stack up [2,3,5]x | It is worth noting that normally when a ad gem appears, the timer for the next ad gem does not start until the ad gem is claimed. Unlocking Ad Gem stack allows the timer to continue up to the new stack introducing more efficient gems/hour by reducing "stopped timers". |
| Missile Barrage Automation | Missile Barrage will activate when its cooldown is complete. | |
| Smart Missile Barrage Automation | Missile Barrage will activate when the tower is hit. | |
| Daily Mission - Set Shard Type | Set the shard type reward for daily missions. | Free Mission Reroll must be unlocked before you can unlock this. |