Boomagon in Batomon Showdown: Ability, Placement and Patch Status

Boomagon is an uncommon Dragon Batomon whose On Cast ability gives the ally behind it +3% Cooldown Speed permanently. Cooldown Speed decides how often a unit casts, and Boomagon’s buff is permanent and can be stacked again and again. So it has become the most universal accelerator in cooldown-engine comps.

The 1.1.0 balance patch on 21 September nerfed it: Cooldown Speed went from 4/8/12% to 3/6/9%, with the developer calling Boomagon the most popular pick in the game. Every figure on this page now reflects the post-1.1.0 build, and this is the first time the studio has published per-level numbers for the unit.

Start with where that number comes from. The official patch notes carry no ability text, and the only per-level figures the studio has published for this unit are the 1.1.0 nerf values. The rarity, type, ability and base numbers on this page come from a community companion site that imports game data (its own label: Balance 22 / Steam build 25377295). Treat that as a community reading. To check your own build. Use the in-game inspect sheet rather than a screenshot or an older guide.

What the ability actually changes

The ability sits on On Cast, so it fires every time Boomagon casts: the ally behind it gains +3% Cooldown Speed, permanently.

Three details make it strong:

• Permanent. Most buffs last for the battle. This one stays, so picking it up early pays off for the rest of the run.
• Stackable. Every trigger adds another +3%, so a run that fields it for dozens of casts multiplies the stat.
• Single-target. The buff only lands on the slot behind it, so Boomagon deals no real damage itself. Its job is to turn one other unit into the engine.

In effect, it turns Cooldown Speed into a resource you can buy. Every payoff that scales with cast frequency — multicast, On Cast triggers, status stacking — grows with it. That is its slot in a team: not the carry, but the precondition for the carry.

Where to place it

The rule is simple and easy to get wrong: Boomagon has to sit in the slot immediately in front of the unit you want to accelerate. Because the buff lands on the ally behind it.

Get it wrong and the buff lands on a unit that does not care about cooldown, and the whole line stays slow. Creator footage shows both uses: one streamer parks it in front of a fast On Cast unit such as Iron Core, pushes the cooldown down to around a second and lets the extra casts start the chain. Others treat it as a generic accelerator. Holding the slot first and deciding later which unit to speed up.

It occupies one of your board slots without dealing damage, so a team running it has one fewer real damage slot. Whether that trade is worth it depends on whether the run offers something behind it worth accelerating.

Why players argue about it

The argument dates back to mid-2026 and splits players into two camps, both of which agree it shows up constantly.

The “it breaks balance” camp: if every comp needs it, cooldown speed stops working as a balance lever, and a run that finds it late is punished too hard. The fixes they suggest are moving it to On Battle Start so it triggers a limited number of times, shifting it to a higher rarity, or removing it so cooldowns can be balanced as designed. The original poster’s words: “every build needs to have a boomagon for at least some part of the game”.

The “it is overrated” camp: it takes front-loaded investment to pay off, and unless it reaches level 2 by around day 4 or 5 it rarely earns its slot; pairing it with Dracana to compensate costs even more slots, and at that point Dracana is the actual carry.

One player flagged early aggression as the real counter — electric multi-hit, poison and burn stacking, the lines that can reach six wins before a cooldown engine comes online.

All of that was written in July 2026, before 1.0.0. The 1.0 release added the Jinto region and 50+ new Batomon and changed the shop pool, so treat those conclusions as history rather than as the current meta. For that. See comps and the current meta.

What the official patches did to it

So the confirmed part is that neither of the two hotfixes after launch touched it. What the 24 August batch changed about it is unknown, because the developer published no list. Any claim about those numbers needs to be checked in game.

Which numbers not to trust

• Per-level and Shiny values. This page deliberately omits them: they were not verified for this page, and the community import predates 1.0.0.
• The “+3%” arithmetic. The ability adds 3% per trigger. What that becomes after dozens of triggers is not a fixed multiplier, so do not treat a single conversion as the answer.
• Cooldown language in older guides. After 11 June 2026 every cooldown effect became Cooldown Speed, so “reduce cooldown by X seconds” no longer exists as a mechanic; see the patch history.

To read the live numbers on your build, use the in-game inspect sheet: on desktop, right-click any Batomon in the shop, in battle, on an event screen or in the Batopedia. On a phone, select it and tap the portrait in the info panel on the right. For how to read an entry, see Batodex and types.

Related pages

• Comps and the current meta: the cooldown, shield, status and electric lines as they stand now.
• Batodex and types: the rarity ladder, how types drive synergies, and how to check whether a number you were told is current.
• Patch notes: the full timeline from the demo through 1.3.0.