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FIRE

The Lava King commands all the Fire units and is guarded by Rock Golem sentries.
Erupt your volcano to gain access to more abilities.
Fire units consume wood for fuel making them strong against Nature units.

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SPARKS

Brawler unit. Sets the enemy on fire.

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SMOKE

Tank unit. Attacks seem to go right through it.

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SPITTING FLAME

Ranged unit. Upgraded attacks shoot farther.

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COAL

Support unit. Grants smolder to allies. Smolder lets allies live a little longer after they are defeated.

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BOULDER

Spellcaster unit. Stuns enemies.

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LIGHTNING

Assassin unit. Initial impact deals bonus damage.

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LAVA MONSTER

Massive unit. Grows stronger with nearby allies.