The One Piece update in Universal Tower Defense X added some of the strongest and most flashy units currently available in the game, with Kaido and Big Mom immediately becoming two of the biggest targets for endgame players. Both units are classified as extremely rare Ruler-tier characters, featuring powerful passives, unique mechanics, and some of the craziest visual effects currently seen in the game.
Getting them is not easy at all, though.
Players are forced into long boss grind sessions, difficult matchmaking, and low drop-rate farming before they can finally evolve and optimize both characters. On top of that, properly building Kaido and Big Mom also requires stat rerolls, ethereal upgrades, relic setups, and strong support units.
This guide covers:
- How to unlock Kaido and Big Mom
- Evolution requirements
- Best stat setups
- Big Mom abilities
- Kaido dragon mechanics
- Farming methods
- Boss rush tips
- Whether the units are actually worth grinding
Farming
Most of the grind for Kaido and Big Mom revolves around:
- Boss Rush
- World Boss stages
- Raid currency farming
- Evolution material drops
- Trait rerolls
- Ethereal upgrades
The process becomes extremely time-consuming because both units require multiple systems stacked together before reaching full power.
Players often spend hours:
- Searching for competent lobbies
- Grinding pity counters
- Farming duplicate materials
- Rerolling stats
- Optimizing relics
The hardest part is not always the boss itself. In many cases, random matchmaking becomes the real challenge because underprepared players can easily ruin runs.
BigMom
Big Mom is one of the first major Emperor units many players focus on because her evolution requirements are slightly easier compared to Kaido.
To evolve her, players need:
- Big Mom unit
- Evolution materials
- Cutlass item
- Raid currency
The Cutlass item can be purchased from the Raid Shop or obtained through Boss Rush drops.
Because Boss Rush also gives additional rewards and currency, many players prefer farming there instead of relying entirely on shop purchases.
BossRush
Boss Rush becomes one of the best farming methods during the One Piece update because it allows players to:
- Farm currency
- Get evolution items
- Test units
- Grind rerolls
- Progress multiple goals at once
The mode features 30 waves and becomes increasingly difficult because of:
- Air enemies
- Shield enemies
- Boss mechanics
- Scaling HP
Strong single-target units perform very well here, especially boss killers.
Zoro
Before Kaido and Big Mom fully enter the picture, evolved Zoro already stands out as one of the strongest boss-focused units in the update.
His biggest strength comes from:
- Critical bleed
- Follow-up attacks
- Boss damage bonuses
Zoro’s bleed mechanic is especially important because the bleed damage scales from his critical damage values. When attacking enemies already affected by Critical Bleed, he gains additional follow-up attacks that massively increase his damage output.
This makes him extremely dangerous against:
- Bosses
- Elite enemies
- High-health targets
However, he also has several weaknesses.
Weaknesses
Zoro struggles heavily against:
- Air enemies
- Shield units
- Certain targeting situations
Despite looking incredible against bosses, he can sometimes underperform in specific maps if:
- He is not targeting strongest enemies
- Bosses move outside range
- Air units overwhelm the stage
Because of this, players usually pair him with proper support or hybrid coverage units.
Stats
Trait optimization becomes very important for late-game units.
The best stat combinations mentioned during the grind included:
- S Damage
- S Range
- S SPA
- SS Damage
Damage-focused traits are especially important for units with:
- Bleed scaling
- Boss damage
- Follow-up mechanics
Cooldown optimization also matters, but certain abilities perform worse if cooldowns become too low.
For example, Zoro’s bleed follow-up interactions work best when enemies remain affected long enough before another attack refreshes the effect.
BigMom
Once evolved, Big Mom becomes an extremely strong AoE and summoner-style unit with multiple layered passives.
Her attacks include:
- Sword slashes
- Lightning attacks
- Flame clouds
- Ghost summons
She also gains companion sub-units:
- Zeus lightning cloud
- Prometheus flame cloud
These companions independently attack enemies and apply status effects.
Passives
Big Mom has one of the most overloaded passive kits in the update.
Her abilities include:
- Stuns
- Damage scaling
- Range scaling
- Ghost summons
- Burn effects
- Electrify effects
- Blackburn effects
- Companion follow-up attacks
One of her strongest mechanics allows her to summon ghost entities whenever enemies are defeated inside her range.
These ghosts:
- Attack enemies
- Scale damage
- Apply debuffs
- Trigger additional explosions
At higher evolution tiers, her entire kit becomes significantly stronger.
Damage
Big Mom performs extremely well during:
- Boss stages
- AoE clearing
- Crowd control
- Sustained fights
Her DPS becomes especially impressive once:
- Fully upgraded
- Equipped with relics
- Given optimized stats
- Combined with support buffs
The visual effects also become absolutely massive once fully upgraded, covering large sections of the map with:
- Purple slashes
- Fire explosions
- Lightning strikes
- Ghost summons
- Cloud attacks
Relics
Relics heavily improve overall performance for endgame units.
Players usually prioritize:
- Damage
- Range
- Summon boosts
- Support scaling
Some relics synergize especially well with Big Mom because her summons inherit portions of her offensive scaling.
Proper relic combinations can massively increase:
- Companion damage
- AoE clearing
- Burn effects
- Overall DPS
Kaido
Kaido is one of the hardest units to obtain because his stage includes:
- Extremely annoying matchmaking
- Difficult clears
- Low drop rates
- Long farming sessions
His evolution item has around an 8% drop rate, which means many players end up hitting pity before finally obtaining him.
Some players even obtain:
- Multiple evolution materials
- Shiny rewards
- Duplicate items
before getting the actual Kaido drop.
Pity
The Kaido grind becomes especially frustrating because:
- Runs take a long time
- Finding good teams is difficult
- Boss clears can fail late
- Drop rates remain inconsistent
Many players report needing:
- 20+ runs
- Multiple hours
- Full pity progress
before finally unlocking him.
Ironically, some players end up obtaining the shiny version before the regular farming process feels complete.
Dragon
Kaido’s biggest mechanic is his Dragon Form.
Unlike most units, Kaido eventually transforms into a controllable dragon once his Rage meter fills.
His Rage system works through:
- Attacking
- Enemy kills
- Time progression
At higher Rage values:
- His damage increases
- His range increases
- His form evolves
- Additional effects activate
Once fully charged, players can manually control Kaido in Dragon Form.
Abilities
Dragon Form gives Kaido access to:
- Beam attacks
- Cyclones
- Fire breath
- Flying movement
- Massive AoE attacks
One of the most impressive things about the form is how smooth the movement feels. The dragon controls are surprisingly fluid and responsive compared to many Roblox flying systems.
Even while manually controlling the dragon, Kaido’s main tower remains active on the map, allowing both forms to contribute damage simultaneously.
Passives
Kaido’s passive list is absurdly large.
His kit includes:
- Burn damage
- Electrify damage
- Stuns
- Follow-up attacks
- Tracking attacks
- Hybrid transformation
- Boss repositioning
- Slow effects
- Dragon Assault triggers
His Dragon Assault passive is particularly strong because it launches additional AoE attacks while applying crowd-control effects.
At higher evolution levels, these passives become even stronger with:
- Increased DOT
- Additional true damage
- Better scaling
- Longer effects