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Io icon.png
Strength primary attribute symbol.png
17 + 2.2
Agility attribute symbol.png
14 + 1.6
Intelligence attribute symbol.png
23 + 1.7
Level Base 1 15 25
Health 200 540 1140 1580
H. Regen 0 1.02 2.87 4.19
Mana 75 328 581 768
M. Regen 0.01 0.93 1.88 2.56
Damage 26‒35 43‒52 73‒82 95‒104
Armor -2 0 3.2 5.49
Spell Dmg 0% 1.64% 3.34% 4.56%
Att / Sec 0.58 0.67 0.8 0.89
Movement Speed 295
Turn Rate 0.7
Vision Range 1800/800
Attack Range 575
Projectile Speed 1200
Attack Animation 0.15+0.4
Base Attack Time 1.7
Magic resistance 25%
Collision Size 24
Legs 0

Io the Wisp is a ranged strength hero who works best as part of a communicative team. With its support-oriented skill set, Io is able to share its strength through Tether and Overcharge, harass enemy heroes out of the lane with Spirits, and materialize itself and an ally anywhere on the map with Relocate. Gank enemy heroes, push undefended lanes, save teammates from deep within enemy territory—the possibilities are endless, and Io features one of the highest skill ceilings in the game.

Io, unlike other heroes, does not need to be facing towards a unit in order to attack, use abilities, or items. It still has a front, marked by an arc-like effect, and a back.


Io Io, the Wisp
Play "…"
Role: Support Support / Escape Escape / Nuker Nuker
Lore: Io is everywhere, and in all things. Denounced by enemies as the great unmaker, worshiped by scholars as the twinkling of a divine eye, Io occupies all planes at once, the merest fraction of its being crossing into physical existence at any one moment.

Like the great twin riders Dark and Light, and yet another ancient traveler whose true history is lost to the ages, Io the Wisp is a Fundamental of the universe—a force older than time, a wanderer from realms far beyond mortal understanding. Io is nothing less than the sum of all attractive and repulsive forces within matter, a sentient manifestation of the charge that bind particles together. It is only in the controlled warping of these forces that Io’s presence can be experienced on the physical plane. A benevolent, cooperative force, Io bonds its strength to others so that the power of allies might be enhanced. Its motives inscrutable, its strength unimaginable, Io moves through the physical plane, the perfect expression of the mysteries of the universe.
Voice: Itself (Responses)


Partially pierces spell immunity. Play
Tether icon.png
Target Unit
Allies / Enemies
Tethers Io to an allied unit, granting bonus movement speed to both. When Io restores health or mana, tethered units target gain 1.5x the amount. Any enemy unit that crosses the tether is slowed. The tether breaks when the allied unit moves too far away, or Io cancels the tether.
Cast Animation: 0.001+0
Cast Range: 1800
Tether Break Distance: 900
Move Speed Bonus: 10%/12%/14%/16%
Move Speed Slow: 100%
Attack Speed Slow: 100
Slow Duration: 0.75/1.25/1.75/2.25 (Talent 0)
Tether Stun Duration: 0 (Talent 0.75/1.25/1.75/2.25)
Tether Duration: 12
Cooldown symbol.png 12
Mana symbol.png 40
Partially pierces spell immunity. Cannot tether spell immune allies. Tether does not break if the tethered ally becomes spell immune. Cannot slow spell immune enemies. Slow persists if debuff was placed before spell immunity and when not dispelled.
Buff Tether: Undispellable.
Buff Tether Haste: Undispellable.
Debuff Tether Slow: Dispellable with any dispel.
The benevolent touch of Io brings strength from between the planes.


  • Has a Break Tether icon.png Break Tether sub-ability that lets Io break the tether while connected with an ally.
  • Tethering a unit that is 700 units or further away causes Io to latch on and pull itself to the target.
    • Pulls Io at a speed of 1000, until coming within 300 range of the target.
    • Can pull Io over impassable terrain and eventually get stuck.
    • Destroys trees within 350 radius around Io right after the pull.
    • If Io breaks the tether while getting pulled to the tethered target, the pull immediately stops.
    • The pull gets interrupted when Io is hit by another spell which applies Forced Movement, but not when Io is disabled.
    • If the pull gets interrupted more than 900 range away from the tethered ally, the link breaks.
  • When the distance between Io and the tethered target gets greater than 700, the link's visual appearance changes.
    • At 700 distance the Tether turns from teal to blue and at 800 it starts flickering.
  • The tethered unit benefits from Overcharge icon.png Overcharge, Relocate icon.png Relocate, and from Io regenerating or replenishing health and mana.
    • Tethered units still benefit from all those effects even when turning invulnerable or when hidden.
    • The health and mana regeneration is only applied to the tethered unit if Io's respective pool is not full.
    • Healing effects like Mekansm icon.png Mekansm are applied to the tethered unit depending on how much health was replenished on Io.
    • Mana restoring effects like Arcane Boots icon.png Arcane Boots are applied fully to the tethered unit if 1 or more mana was replenished on Io.
  • An enemy unit may only be slowed (Talent stunned) once per cast of Tether.
  • If Io is tethered to an invisible unit, his enemies can only see a fake link leading to the invisible unit's last known location.

Break Tether
Break Tether icon.png
No Target
Break the link to the tethered unit.
Cast Animation: 0+0
Cooldown symbol.png 1


  • Replaces Tether icon.png Tether until the Tether is broken.
  • The cast of Break Tether is not registered as a spell cast and thus does not proc any on-cast effects.

Does not pierce spell immunity. Play
Spirits icon.png
No Target
Summon five particle spirits that dance in a circle around Io. If a particle collides with an enemy hero, it explodes, damaging all enemy units in an area around it. Creeps take minor damage from touching a particle spirit, but do not cause them to explode. When its duration ends, any remaining spirits explode.
Cast Animation: 0+0
Spirits Spawn Radius: 150
Collision Radius: 70
Explosion Radius: 300
Collision Damage: 8/14/20/26
Explosion Damage: 25/50/75/100 (Talent 175/200/225/250)
Spirits Duration: 19
Cooldown symbol.png 20/18/16/14
Mana symbol.png 150
Buff Spirits: Undispellable.
Io twists the particles of the universe with his unimaginable capabilities.


  • Upon use, Io gains 2 sub-abilities to control how far away the spirits orbit.
  • 5 spirits are summoned over the course of four seconds so that the distance between each spirit is equal.
  • The spirits complete a revolution every ~2.3 seconds regardless of distance from Io.
    • Their angular velocity is constant, meaning that spirits move more quickly when further from Io.
  • When a non-hero unit comes within the 70 collision radius of the spirits, it takes the collision damage.
  • When a hero comes within collision radius, the spirit explodes and deals the explosion damage within 300 radius to every enemy.
  • Remaining spirits detonate simultaneously at the end of the duration or if recast, dealing the explosion damage to nearby enemy units.
  • Spirits provide 150 radius flying vision for 3 seconds at the location where they collided with a hero.
    • They do not provide vision when exploding caused by expiring or recasting.
  • Unlike most other spells, the spirits are visible to the enemy even if Io is invisible.
  • Can deal up to 125/250/375/500 (Talent 875/1000/1125/1250) damage to a single unit when all 5 spirits explode on a target (before reductions).

Spirits In
Spirits In icon.png
Calls the spirits closer to you. Can be toggled on and off.
Cast Animation: 0+0
Minimum Distance: 100
Cooldown symbol.png 0


  • Only active while the Spirits icon.png Spirits buff is on Io.
  • The toggling of Spirits In is not registered as a spell cast and thus does not proc any on-cast effects.
  • Does not interrupt Io's channeling spells upon cast.
  • Moves the spirits towards Io with 250ms. It takes 3.1 seconds from moving the spirits from max to min distance.

Spirits Out
Spirits Out icon.png
Sends the spirits farther away from you. Can be toggled on and off.
Cast Animation: 0+0
Maximum Distance: 875
Cooldown symbol.png 0


  • Only active while the Spirits icon.png Spirits buff is on Io.
  • The toggling of Spirits Out is not registered as a spell cast and thus does not proc any on-cast effects.
  • Does not interrupt Io's channeling spells upon cast.
  • Moves the spirits away from Io with 250ms. It takes 3.1 seconds from moving the spirits from min to max distance.

Pierces spell immunity. Play
Overcharge icon.png
Self / Allies
Io gains bonus attack speed and damage reduction, at the cost of draining a percentage of its current health and mana per second. If Io is tethered to an ally, that unit also gains the bonuses.
Cast Animation: 0+0
Current Health & Mana Cost per Second: 6%
Attack Speed Bonus: 40/50/60/70
Damage Reduction: 5%/10%/15%/20%
Cooldown symbol.png 2
Buff Overcharge: Undispellable.
Drawing on the energy of matter from all worlds, Io begins the unravelling of time.


  • Overcharge does not interrupt Io's channeling spells upon cast.
  • The toggling of Overcharge is not registered as a spell cast and thus does not proc any on-cast effects.
  • A tethered ally is affected by the damage reduction and attack speed, but only Io pays the drain in hp and mana.
  • Drains 1.2% of current health and mana in 0.2 second intervals.
  • Io and the tethered ally's effective health are increased by 5.26%/11.11%/17.65%/25%.
    • This quickly diminishes for Io because of the health loss.

Pierces spell immunity. Play
Relocate icon.png
Target Point
Self / Allied Heroes
Teleports Io and any tethered ally to any location. After the spell expires Io and any tethered ally will return to their original location. Double-click to teleport to your team's base fountain.
Cast Animation: 0+0.53
Cast Range: Global
Effect Delay: 2.7/2.35/2
Duration: 12
Cooldown symbol.png 100/80/60
Mana symbol.png 100
Buff Relocate Teleporting: Undispellable.
Buff Relocate Return: Undispellable.
Io is the embodiment of the mystery of the universe.


  • Double-clicking the ability automatically targets the team's fountain area.
  • If Io is interrupted during the casting delay, Relocate gets cancelled.
    • Can be cast while Io is rooted, but the teleport does not happen when still rooted after the delay.
    • Disabling the tethered ally of Io does not prevent the ally from getting teleported if Io successfully does so.
    • The returning teleportation cannot be prevented.
  • Enemies get a notification on their minimap during the teleport delay, showing them where Relocate was targeted.
    • Creates a visual effect at the targeted point during the teleport delay, which is visible to everyone.
    • Creates a visual effect at Io's position before the teleport happens, which also is visible to everyone.
  • Provides 300 radius flying vision at the targeted point during the effect delay. Does not provide vision otherwise.
  • Relocate interrupts channeling spells and every current order of Io and the tethered ally both on initial teleport, and when going back.
  • If Io is tethered to a unit, Tether icon.png Tether's duration is refreshed before and after the teleport delay.
  • Io may sever its tether at any time to prevent bringing an ally back.
  • Destroys trees within 300 radius around Io upon both teleports.
  • The Disablehelp option prevents Io from relocating the respective ally.


Hero Talents
+150 Spirits icon.png Spirits Damage 25 Tether icon.png Tether Stuns
+120 Gold/Min 20 +20 Health Regen
+10 Strength attribute symbol.png Strength 15 +10 Mana Regen
+6 Armor 10 +10% Magic Resistance
  • The magic resistance stacks multiplicatively with other sources of magic resistance.
  • The armor is added as bonus armor, and therefore does not benefit illusions.
  • Health regen and mana regen are added as bonuses and do not benefit illusions.
  • The Tether icon.png Tether slow gets replaced by the stun. The stun duration equals the slow duration.
  • The damage upgrade to Spirits icon.png Spirits only affects the explosion damage, and not the passing damage.

Recommended items[edit]




  • Magic Wand icon.png Magic Wand is a cheap upgrade from Magic Stick icon.png Magic Stick. It helps Io heal allies even more.
  • Mekansm icon.png Mekansm heals Io's partner for 625 health, as opposed to the standard 250.
  • Bottle (Full) icon.png Bottle is useful for restoring both ally's health and mana.
  • Arcane Boots icon.png Arcane Boots can be used to restore a large amount of mana to Io and his allies, thanks to Tether.
  • Tranquil Boots (Active) icon.png Tranquil Boots can also be considered for healing allies.







  • Io is the name of a priestess of Hera in Greek Mythology. She was seduced by Zeus and subsequently incurred Hera's wrath.
    • Io is also the name of one of four Galilean moons of Jupiter, which was named after the same character in Greek Mythology.
  • Io's fun names in DotA were Weird Ball and Santelmo. Santelmo may refer to St. Elmo's Fire, a weather phenomenon that creates sparks of bright energy similar to that of lightning, mostly occurring from sharply pointed structures.
  • Enigma minimap icon.png Enigma, Io minimap icon.png Io, Keeper of the Light minimap icon.png Keeper of the Light, and Chaos Knight minimap icon.png Chaos Knight together represent the four fundamental forces of the universe with Io representing the electromagnetic force, as alluded to in his lore as the force that binds all matter together, as well as his abilities which mostly rely on being bound to a partner to achieve maximum effect.