Heroes Unrealeased

Mortar Team - STR type hero

Skills:
Concussive Shot
Relevant information shows that it silences and slow enemy units.

Bomb Bomb
Unknown skill.

Flash Bomb
Relevant information shows it applies Drunken Haze that causes enemy units to miss 80% of their attacks.

Siege Form
A skill that toggles between two forms: base hero and Siege form. The toggle has a 4 second CD. Reduces ms of the Mortar team to 100 but also increases attack damage by 50/100/150 and raises attack range to 1000/1250/1500. The Mortar Team can be made to attack ground, and all attacks hit in an AoE. When we tried to test orbs with this attack, the game crashed.

Priest - INT type hero

Skills:
Holy Shackles
Sends out beams of light to the closest enemy units. Once these beams hit, the effect applied to the enemy is the same as Searing Chain

Chill
Silences a single enemy and deals damage.

Focus
Increases damage by 100 on an allied target for x attacks, but also lowers their movement speed.

Divine Intervention
Dooms a target and prevents them attacking, but makes them invulnerable (literally, they receive invulnerable status in the same way Omnislash provides.)

Wyvern Outrider - AGI type hero

Skills:
Sonic Boom
Rushes towards target point up to x range away, but stops at the first enemy unit it makes contact with, stunning and dealing damage. This skill seems to be blocked by trees.

Wind Blast
Deals damage in a small AoE after a short delay based of a formula that seems to be partially derived off of the hero's AGI.

Wind Barrier
Banshee's Anti-magic Shell on a target ally as well as increasing their movement speed.

Prevailing Winds
Cyclones everything in the area of effect (except buildings). After the cyclone ends, friendly units gain bonus movement speed whilst enemy units are slowed.
Wind Barrier seems to apply some extra armor and attack speed based on some ability information.

Edgewalker - INT type hero

Skills:
Death Watch
Targets an allied unit and places a buff on them for ~10 seconds. If the unit is killed by an enemy, the unit responsible for the killing blow takes damage and is stunned.

Reality Shift
Places a ward which causes nearby enemy units to become ethereal.

Fatal Attraction
Whenever Edge Walker casts a skill, all enemy units in an AoE of x are pulled y distance towards him.

Haunting Echos
This skill seems to passively spawn a wisp next to Edgewalker at intervals of x seconds. He can have up to a maximum of 3 wisps around him at a given time. Casting this skill destroys one of the wisps and silences and deals damage in a small AoE. The CD of this skill is very short, but it's limited by the wisp spawns.

Dragonhawk - INT type hero

Skills:
Conjure Force
Deals damage and ensnares units in an AoE between 400 and 600 units from the hero. Units closer than 400 are not effected.

Arcane Seal
Seems to be the same as Dragonhawk Rider's Arcane Seal skill. Well, it would make sense as this hero is named Dragonhawk. Prototype?

Thrust
Pushes target away from the caster by ~350 units. The skill heals allies it's cast on and harms enemies. Can be targeted on self, will push in direction of facing if cast on self.

Divine Wrath
Targets a single ally and causes the caster to begin to channel. The targeted unit takes no damage for the duration of the channel. At the end of the channel, Dragonhawk gains a sub ability that allows her to launch a projectile that deals the negated damage in an AoE.

Target Divine Wrath (Divine Wrath's Sub-Skill)
Launches a missile in the targeted angle. Deals damage proportional to blocked damage. For best results, tank the fountain and then get a rampage.

Ghost Revenant - INT type hero

Skills:
Wraith
Puts the hero into the Ethereal state for x seconds, at the same time increasing MS. The skill can be cast again to end the Ethereal state early, although at max level the CD and duration of the skill seem to be the same, allowing for the skill to be on all time.

Blackjack
Fires 3 orbs in parralel line that each move at 800 units per second. These orbs deal damage and stunn any units caught at the tip of the AoE.

Miasma
Deals damage to all enemy units in an x AoE and applies a buff. This buff reveals invis units and deals damage over time (It's essentially Dust with damage).

Exhaustion
Reduces the MS of all enemy units on the map to 100.

Thanks to dota-blog.com