ToE H5/HoF
Academy - Wizard Dungeon - Warlock Fortress - Runemage Haven - Knight Inferno - Demon Lord Necropolis - Necromancer Sylvan - Ranger Hero Specials
Academy - Wizard

Disrupter

Specializes in Curse of Vulnerability so that the spell not only decreases the defense of the target, but also inflicts damage. Damage inflicted depends on hero level.

Hero:

Flame Wielder

Effective Spellpower of the hero is increased when casting fire-based spells. Modifier depends on hero level.

Hero:

Golem Crafter

Specializes in Golems. Iron Golems and Steel Golems in hero's army gain +1 to their attack and defense for every two levels of the hero, starting on first level.

Hero:

Gremlin Master

Specializes in Gremlins. Gremlins and Master Gremlins in hero's army gain +1 to their attack and defense for every two levels of the hero, starting on first level.

Hero:

Master of Elements

Every time a friendly stack dies, a group of elementals enters combat at the hero's side. The number of elementals increases depending on hero level. In addition, Summon Elementals and Summon Phoenix spells cast by the hero are more powerful.

Hero:

Mentor

Specializes in Mage. Mage and Archmage are more efficient depending on hero level

Hero:

Mystic

Hero is able to restore mana in combat gradually by himself. Restoration speed depends on hero level.

Hero:

Spell Twister

The Spell Twister ability increases the chance that redirected enemy spells land on one of the enemy units instead of going in a random direction.

Hero:

Windspeaker

Hero's turns come faster in combat depending on hero level.

Hero:
Dungeon - Warlock

Black Hand

Specializes in Scouts. Scouts and Assassins in hero's army gain +1 to their attack and defense for every two levels of the hero, starting on first level.

Hero:

Blood Mistress

Specializes in Blood Maidens. Blood Maidens and Blood Furies in hero's army gain +1 to their attack and defense for every two levels of the hero, starting on first level.

Hero:

Catalyst

Empowered spells mana cost is reduced by 5% and + additional 1% per hero level.

Hero:

Coven Mistress

Shadow Witches and Shadow Matriarchs have a chance to make a free additional shot at the hero's current target. Chance increases depending on hero level.

Hero:

Dark Mystic

Dark Ritual ability is more powerful, enabling the hero to regenerate mana even beyond the normal max mana cap. Amount regenerated over the cap depends on hero level.

Hero:

Intimidate

Enemy units have penalty to initiative, depending on hero level.

Hero:

Lizard Breeder

Specializes in Raiders. Raiders's special attack Lizard Bite deals more damage, depending on hero level.

Hero:

Master of Initiative

All creatures in hero's army get +1% to their Initiative and enemy creatures get -1% for their Initiative for every level of the hero.

Hero:

Poison Master

Enemy units may enter the combat already poisoned, chances depend on hero level.

Hero:

Shadow Dancer

Less damage is suffered from distant attacks, reduction depends on hero level.

Hero:

Slave Driver

Specializes in Minotaurs. All Minotaurs and Minotaur Guards in hero's army gain +1 to their attack and defense for every two levels of the hero, starting on first level.

Hero:
Fortress - Runemage

Border Guard

Hero has a bonus to his Defense (+1 Defense for each 2 hero levels) if fights are one day away from owned city.

Hero:

Golden Tongue

Neutral creatures are more likely to join this hero. Moreover victories provide this hero with gold and resources.

Hero:

Keeper of the Flame

Specialises in Priests. Rune Priests and Patriarchs in hero's army gain +1 to their Offense and Defense for every two levels of the hero, starting on first level.

Hero:

King of the Stone Halls

All creatures in hero's army have "Rune of Thunderclap" effect permanently active (refreshes at the start of creature turn).

Hero:

Master of the Runes

With each level-up, the hero can spontaneously learn one more Runic Spell.

Hero:

Protector

Specialises in Defenders. Defenders in hero's army gain +1 to their Offense and Defense for every two levels, and +1 to their Hit Points for every five levels of the hero.

Hero:

Rider

Specialises in Riders. Bear Riders and Blackbear Riders in hero's army gain +1 to their Offense and Defense for every two levels of the hero, starting on first level.

Hero:

Rune Artist

Chances of success with Fine Rune feat are increased by 20% from the start and by +1% for every level.

Hero:

Sacred Hammer

Each time the hero casts a light magic spell on a friendly creature, there is a chance that the ‘Righteous Might' spell will be cast freely upon the affected unit.

Hero:

Sharp Blade

Specialises in Spearwielders and Skirmishers. Spearwielders and Skirmishers in hero's army gain +1 to their Offense and Defense for every two levels of the hero, starting on first level.

Hero:

Stormcaller

Lightning-based spells of this hero are irresistible for the enemies (immunities and magic-proof still apply).

Hero:
Haven - Knight

Archer Commander

All Archers and Marksmen in hero's army gain +1 to their attack and defense for every two levels of the hero, starting on first level.

Hero:

Beloved of the People

All Peasants and Conscripts in hero's army gain +1 to their attack and defense for every two levels of the hero, starting on first level. Also, all Peasants in hero's army earn another +1 gold piece in kingdom treasury every day, in addition to their Tax Payer ability.

Hero:

Cavalry Commander

Cavaliers and Paladins in hero's army get additional jousting bonus as hero gains new levels. Hero's "Retaliation Strike" ability is more powerful.

Hero:

Dragonblessed

All creatures in hero's army get a Bless effect for the whole combat.

Hero:

Griffin Trainer

All Griffins and Imperial Griffins in hero's army gain +1 to their attack and defense for every two levels of the hero, starting on first level. Griffins get Battle Dive Ability.

Hero:

Infantry Commander

All Footmen and Squires in hero's army gain +1 to their attack and defense for every two levels of the hero, starting on first level.

Hero:

Paragon Knight

The effect of Benediction increases as hero gains new levels. Mana used for casting Light Magic spells are reduced by 1.

Hero:

Pathfinder

Hero's movement points are increased by 1% per every two hero level.

Hero:

Siege Engineer

Ballistae receive +1 to their attack for every level of hero. Catapult's chance to hit the wall is increased by 2% for every hero level.

Hero:

Suzerain

Hero contributes 250 gold pieces in kingdom treasury per day. Hero has a 2% per level discount for troop training in Haven towns.

Hero:

Windrider

The effect of Haste spell is increased by 1% for every hero level.

Hero:
Inferno - Demon Lord

Aura of Swiftness

The initiative of all creatures in hero's army is increased by 1% per hero level.

Hero:

Chosen of Chaos

Luck of all hero's troops is increased by 1. Also, enemy hero can not use Tactics ability in combat.

Hero:

Gate Keeper

The number of creatures called through the Gating increases by 1% per hero level.

Hero:

Hound Master

All Hell Hounds and Cerberi in hero's army gain +1 to their attack and defense every two levels of the hero, starting on first level.

Hero:

Iron Maiden

Ballista's shots under hero's command achieves fireball effect. Spell power of this fireball increases by +1 for every five hero's level.

Hero:

Mindreaver

The Confusion spell has an additional effect of decreasing target's mana by one point per every hero level.

Hero:

Rusher

Hero's movement points are increased by 5% instantly and by + 1% per every four level. The cost of Teleport spell is reduced by half.

Hero:

Spellbreaker

All creatures in hero's army gain 5% Magic Resistance and + 1% per hero level.

Hero:

Temptress

All Succubi and Succubus Mistress in hero's army gain +1 to their attack and defense for every two levels of the hero, starting on first level.

Hero:
Necropolis - Necromancer

Banshee

The effect of Banshee Howl ability increases as hero gains new levels.

Hero:

Death Lord

All neutral undead creatures will join hero's army. The number joining army is 50% of initial number + 2% per hero level.

Hero:

Embalmer

The First Aid Tent will heal 5 more hit points per hero level. The damage in case of Plague Tent ability is also increased.

Hero:

Reanimator

The Raise Dead spell has increased effect. The spellpower of this spell is increased by 1 for every five levels of hero, starting on first level.

Hero:

Souldrinker

The Curse of Weakness spell not only lowers creature's damage, but also reduces creature's defense by 1 for every three levels of hero, starting on first level.

Hero:

Soulhunter

Every time a group of enemy creatures dies it is replaced by a group of friendly Ghosts for the time of combat. The number of Ghosts depends on hero's level.

Hero:

Spellwringer

If enemy hero casts any spell, it can be blocked in his or her spellbook making it impossible to cast that spell again in this combat. The probability of blocking increases as hero gains new levels. The higher the spell's circle, the harder it is to block it.

Hero:

Vampire Princess

All Vampires and Vampire Lords in hero's army gain +1 to their attack and defense for every two levels of the hero, starting on first level.

Hero:

Zombie Lord

All Zombies and Plague Zombies in hero's army gain +1 to their attack and defense for every two levels of the hero, starting on first level.

Hero:
Sylvan - Ranger

Battle-Hardened

All experience that hero gains after battles is increased by 2% per hero level.

Hero:

Blade Master

All Blade Dancers and War Dancers in hero's army gain +1 to their attack and defense for every two levels of the hero, starting on first level.

Hero:

Elven Fury

Blade Dancer, War Dancer, Hunter, Master Hunter, Druid, Druid Elder get Enraged ability.

Hero:

Master of the Hunt

All Hunters and Master Hunters in hero's army gain +1 to their attack and defense for every two levels of the hero, starting on first level.

Hero:

Storm of Arrows

Arrow barrage of the enemy ranks at the start of every battle, total damage depends on hero level. (Applies to Sylvan ranged units only).

Hero:

Swarm Queen

Wasp Swarm spell is more effective depending on hero level.

Hero:

Swift Striker

Creature's in hero's army have a +0.5% +2% per hero level bonus to their initiative at the start of combat.

Hero:

Sword of Sylanna

All Sylvan creatures under hero's command inflict +2% more damage to favoured enemy for every hero's level

Hero:

Unicorn Maiden

All Unicorns and Silver Unicorns in hero's army gain +1 to their attack and defense for every two levels of the hero, starting on first level.

Hero:
This information comes from the Heroes V release version (v2.1).

Thanks to sfidanza for creating the Heroes V skills and abilities pages!
Thanks to Valeriy for optimisation!