Alleria, the Mistress of the Stars.

This is a repost of the idea that I submitted in the hero idea contest, just wanted to post it here so people could discuss it and people who haven't seen it before can see it here!

Alleria, the Mistress of the Stars
High in the sky, high in space sits a large glistening temple. Inside the temple are countless tiny stars and a royal throne. Atop the throne sits Alleria, the Misterss of the Stars. From her throne she can see all across the universe, she can predict when stars will die and when stars will be born anew, but a disturbance on a far planet has been worrying her for days, a battle is brewing which could disturb the alignment of the stars. Alleria joins the Radiant side in the battle of the ancients, because if Dire receive their powers, the universe could be in peril.
Attributes:
Health: 501
Mana: 260
Strength: 20
Agility: 18
Intelligence: 21
Armour: 2
Movement Speed: 305
Alleria is a ranged intelligence hero who excels at keeping foes at bay in lane, thus she is a great support. She has 2 stunning abilities, a small but handy healing ability and a devastating ultimate which can change the tide of battle if pulled off correctly.

Q) Luminous Flare:
Alleria launches a bright flare at an enemy, which stuns them and deals moderate damage.
Alleria can draw power from the stars, conjuring up bright bolts of energy to strike down foes.
Stun Duration: 1.4/1.5/1.6/1.7
Damage: 100/125/150/200
Mana: 150/160/165/170 Cooldown: 10/9/8/7

W) Celestial Showers:
Alleria shatters a star into a renewing dust, sprinkling it on an area and healing allies inside.
Alleria puts to use the dead stars in the sky, using their final sliver of power to aid others.
Radius: 375
Healing: 100/150/200/250
Mana: 160/170/180/190 Cooldown: 25/23/21/19

E) Incandescent Ray:
Alleria heats a small star in the sky, causing it to emit a large beam of energy at a target point in the battle field, stuns for a huge duration and deals large damage, but has a long delay.
Alleria has the power to heat stars to such intense temperatures that they release a huge ray of light down to earth.
Stun: 2/2.5/3/3.5
Radius: 230
Damage: 150/200/250/300
Mana: 130/140/150/160 Cooldown: 19/17/15/13

Ultimate: R) Star Cannon:
Alleria summons all the power from the nearby stars to charge up one devastating cannon blast. This ability can be cast anywhere within a huge radius. The start of the ability is a channel, and can be stopped at any time to release the bolt. The channeling time can be up to ten seconds, each second channeled increases the damage and stun.
Alleria summons all of the stars celestial powers, hoping to put an end to the battle with one powerful shot.
Damage Increase per Second: 30/40/50 (scepter 60)
Stun Increase per Second: .2/.3/.4
Range: 2500
Mana: 200/300/400 Cooldown: 120/110/100