Units are the towers you place along the path in Universal Tower Defense, and almost every one comes from the Summon building in the main square. Each unit has an element, a field position, and a passive ability that defines its role, so picking the right ones decides how quickly you clear Story, Infinite, and Virtual Realm content.
How summoning and unit slots work
To collect units, walk to the Summon building, talk to the NPC at the desk, and choose a banner. A single pull costs 50 gems and a ten-pull costs 500 gems. You confirm it worked when the new unit lands in your Units menu and becomes equippable.
Your battle loadout holds six slots, but they unlock over time. You start with four, the fifth opens at level 15, and the sixth opens at level 30. Early on you can place the same unit more than once if you are short on characters, which helps when you only have one strong damage dealer.
You can pull most units this way, but some are locked behind Story progress, quests, evolution, or special events rather than the standard banner.
Unit rarity and summon rates
Rarity sets the baseline power of a unit and how rare it is to pull. Mythics are the chase tier and almost never appear from a single pull, which is why ten-pulls and gem stockpiling matter.
| Rarity | Summon rate | What to expect |
|---|---|---|
| Mythic | 0.5% | Top-end DPS and meta carries |
| Legendary | 2% | Strong mid-game damage and support |
| Epic | 16% | Reliable early main damage dealers |
| Rare | 81.5% | Filler and early placements |
Best units tier list
The strongest summonable units cluster at the top of the ranking, with S-tier acting as the meta and A-tier serving as solid alternatives. B-tier units are situational, while C and D are mostly early-game or farm picks.
| Tier | Units |
|---|---|
| S | Admiral (Magma), Berserker (Enraged), Dragon Guy (Silverite), Jinoo (Monarch), Ice Empress (Frost), Jangluu (Eclipse), Phantom Captain (Carrier), Psycho, King Sailor, Ancient Shinobi, Miku (Super Star) |
| A | Cyborg (Fearless), Kriatu (Cheater), Ronin Obito, Rule (Room), Sasku (Chakra), Spade (Donut), Shunks (Conqueror), Koyote (Number One), Bambee (Blitz), Tierabel (Hydro), Robot 17 & 18, Fallen Prince, Lord of Flies, Water God, Ichiko (Rage), Bio-Android (Imperfect), Migumen (Finale), Sharpshooter (Precision), Unparalleled Armor, Majestic Armor |
| B | Footballer (Ego), Shakumira Evo, Ultiorra (Oblivion), Rogue Oni, Scarlet Maid (World) |
| C | Gen, Masked Ninja, Mob (100%), Nejo, Orahemi, Pebble, Namu, Nutaru (Kid), Nellee |
| D | Fastcart, Ruka, Zorus, Ranji, Gaaru, Laffy, Lulu, Bulmo, Grommjaw |
A few abilities explain the rankings. Berserker ignores 30% of elemental armor restrictions, Psycho applies wind shear and makes confused enemies take 15% more damage, and Spade applies a burn that bypasses armor damage reduction. Jinoo unlocks new summons as he levels, gaining Shadow Bear at 40, Shadow Dragon at 60, Shadow Knight at 80, and Ant King at 100.
Traits that matter most
Traits are random modifiers added through Trait Rerolls, and they can swing a unit's power hard. Reroll items come from codes and quests, and you apply them at the upgrade building marked with the Traits logo.
| Trait | Drop rate | Effect |
|---|---|---|
| Ruler | 0.1% | Best in game; large stat boost and changes placement mechanics |
| Sacred | 0.3% | Strong damage boost; alternative to Ruler for main DPS |
| Scarred | 0.3% | +25% Damage, reduced cooldown, +25% Range |
| Duelist | 0.8% | +25% Crit Chance, +Range, +Boss Damage |
| Fortunate | — | Increases gold income; essential for Speed Cart |
Building a unit: relics, etherealization, and evolution
Raw rarity is only the starting point. Three systems push a unit from usable to endgame-ready.
Relics are equipment pieces split into Hat, Top, and Bottom slots, and they add substats such as Crit Damage, DOT Damage, Cooldown, and Damage. Match the relic to the unit's job rather than slotting any piece. One trap to remember is that Crit Rate from relics is multiplicative, not additive, so a +37.5% Crit Rate relic only takes a 15% base to roughly 20%, not 52.5%.
Etherealization feeds duplicate copies into a main unit to raise its Ethereal Level from E1 toward E6, unlocking passives and stat boosts at each step. Never sell core duplicates. Mythics like Ace and Spade reach E6 far more easily than Secret units such as Sun Jin Wu, which need seven copies at an extremely low drop rate.
Evolution transforms eligible Mythics using Takedowns and specific materials. Plan on roughly 5,000 to 6,200 kills plus fragments and unit-specific items. Story Act 1 is the fastest farm for Takedowns because enemies are weak and plentiful, while Infinite mode is too slow for that purpose.
Secret, evolved, and Synchro units
Beyond the banner roster sit the highest-end units. Secret units come from quests and raids, while Boundless and Synchro forms represent the current damage ceiling. Synchro Drive fuses two maxed units into one, and the result carries the stats, traits, and relics of a single chosen unit. Synchro Clash instead triggers a combined attack when two specific evolved units sit in range of each other at max upgrade.
If you want a leader buff, place Triple Threat (Unrivaled) or Kind Sailor (Unrivaled) in the first slot, since those buffs only apply from the leader position. For economy, Speed Cart remains the main gold generator, and grabbing "The Lovers" card in Virtual Realm grants an extra placement so you can run two of them.
The fastest path to a strong roster is simple. Save gems for ten-pulls, push Story Mode to bank Gems and clear bonuses, and funnel your rerolls, relics, and duplicates into one or two S-tier carries instead of spreading them thin across the whole collection.