Hero Spells are the third major spell in Kingdom Rush: Origins. The spell has different effects depending on the hero you use, resulting in varying cool-down times. Though the Hero Spell can be upgraded in the Hero Room just like any other skill, it can be used immediately in a level without any upgrades. This means each spell has four levels of strength; the initial base plus three additional upgrades.
- ARROW STORM - Eridan - Blankets a wide area with a volley of 14/17/21/28 arrows, each dealing 24/31/42/65 damage. Cooldown: 40 seconds.
- ELEMENTAL STORM - Arivan - Summons an elemental tornado that slows and freezes enemies, shoots lightning and deals 150/210/320/500 area damage over 5/6/8/10 seconds. Cooldown: 80 seconds.
- FAERY DUST - Catha - A quick spell that stuns all enemies in an area for 2/3/4.5/8 seconds. Cooldown: 25 seconds.
- CHANGELING - Razz and Rags - Transfigures up to 2/4/6/8 enemies into allied fighting Ragdolls for 4/5/6/7 seconds. Cooldown: 60 seconds.
- HEAVENLY CHAOS - Lilith - A 50/50 chance to summon Fallen Angels or a rain of fire dealing 200/400/800/1200 damage. Cooldown: 60 seconds.
- VINDICATOR - Reg'son - Vindicator slays any single target, with a cooldown of 120/100/70/50 seconds. Deals 2000 damage to (minibosses)
- PANDAEMONIUM - Xin - Calls 2/4/5/6 panda warriors that quickly attack enemies, each dealing 80/120/160/180 damage. Cooldown: 35 seconds.
- SWORN DEFENDERS - Prince Denas - Calls 2/3/4/5 members of the Kingsguard to aid him in battling the hordes of evil. Cooldown: 60 seconds.
- FATE SEALED - Lynn - Does 200/300/450/600 damage in 5 secs to its target. Explodes dealing 100/150/175/200 area damage if killed. Cooldown: 30 seconds.
- DARK PACT - Vez'nan - Summons a mighty demon to fight enemies for 30 seconds, dealing 30-50/50-90/65-115/80-130 damage on every attack. Cooldown: 120 seconds.
- SAPPHIRE FANGS - Durax - Summons sharp spikes over a wide area dealing 300/600/900/1200 True Damage distributed among enemies. Cooldown: 45 seconds.
- This spell's description is bugged, stating the damage to be 320/480/960 damage when it really is more.
- NATURE'S WRATH - Bravebark - Densely covers a wide area with 6/9/12/15 spiked vines, each dealing 30/40/50/60 area damage. Stuns enemies struck by it for 1 second. Cooldown: 30 seconds.
- GUARDIAN LIONS - Bruce - Summons 2/2/3/4 Guardian Lions that deal 80/140/360/720 damage and disable their target for 2/2/3/4 seconds. Cooldown: 50 seconds.
- EMBER STORM - Phoenix - Sets an explosive egg that deals 20-65/55-105/120-220/200-400 area damage. Cooldown: 20 seconds.
- PEWPEW DRONES - Wilbur - Calls 4 drones that attack enemies dealing /128/192/256 damage for 8 seconds.
- DRAGON RAGE - Faustus - Calls 3 dragonlings that ignite the path, dealing 60/90/150/210 area damage each over 6 seconds. Cooldown: 40 seconds.