Universal Tower Defense: Ragna Raid Tier List

【Winter Update】Master the mechanics. Solo the Frostbite Dragon in UTD.

Boss Mechanic Kill Squad Full Tier List Walkthrough FAQ
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Boss Mechanic: Hyper Armor

Critical

Understanding the Frostbite Dragon

The Frostbite Dragon is not a normal enemy. He has Hyper Armor which makes him nearly invincible without the proper counter.

  • Effect — Reduces ALL incoming damage by 90%
  • Counter — Apply "Defense Break" using Kenpachi
  • Visual Cue — A cracked shield icon appears above his head

The Kill Squad

Essential Units
SSS TIER

Ace — The Burner

Main Boss DPS

While armor is broken, Ace stacks burn. With Astral trait, this burn bypasses boss defense scaling.

Trait: Astral (Mandatory) Synergy: Kenpachi (Breaker)
SSS TIER

Kenpachi — The Breaker

Enabler

He does 0 damage himself, but he enables your Ace to deal 1000% damage. Mandatory for any Ragna run.

Role: Defense Break Priority: MUST HAVE

Complete Tier List

Updated Jan 2026
Tier Unit Role Meta Note
SSS Ace DOT Stacker The Boss Killer. 100+ Burn stacks melt HP.
SSS Kenpachi Armor Breaker Required to remove 90% Dmg Reduction.
SS Spade Air DOT Can hit flying enemies in Waves 1-14 reliably.
SS Nei (E6) Knockback Keeps the boss away from base while burn ticks.
S Lelouch Support Rewinds the boss if he gets too close.
A Ragna Raw DPS Strong for minions, weak for boss (no DOT).
A Admiral Slow Magma pools help with crowd control.

Three Steps to Victory

Step-by-Step
1
The Setup Wave 1-14

The raid spawns flying enemies. Ragna (unit) is bad here.

  • Place your kill squad at the END of the track.
  • This gives you maximum time to stack burns during boss walk.
  • Use Spade or Ace for early wave clears.
2
The Break Boss Entry

The Dragon spawns with a shield.

  • Wait for him to enter Kenpachi's range.
  • Verify the "Broken Shield" icon appears.
  • If not, use Lelouch to rewind him back into range.
3
The Burn Loop

Once armor is broken, Ace starts stacking.

  • Look for RED damage numbers.
  • Use Nei (E6) to knock him back continuously.
  • Do not let him reach the base until burn stacks > 50.

Frequently Asked Questions

What if I don't have Kenpachi?
You cannot kill the boss efficiently. Ask a friend to bring him, or buy him from the market. He is mandatory.
Does 2 Ace units stack burn faster?
Yes. Placing multiple Ace units will reach the stack cap faster, but the cap itself is determined by Trait/Relic.