Maiev Shadowsong by MagicPants

Level 1:

Undying Wrath:
Quest: Every Minion you kill gives you 0.1 Attack Damage. Every Takedown gives 1 Attack Damage.
Reward: Once you reach 20 Attack Damage, receive an additional 20 Attack damage.

Shadow Lunge:
Increases the range of Shadow Strike by 20%.

Disappearing Act:
While Vanish is active, activate again to dash in the direction you are facing.

Level 4:

Searing Attacks:
Activate to increase Basic Attack damage by 50% for 5 seconds. Each attack costs 15 Mana.

Vanishing Act:
Vanish's duration is increased by 2 seconds.

Blood for Blood:
Activate to deal 10% of target enemy Hero's Max Health and heal for twice that amount.

Level 7:

Strike from the Shadows:
Shadow Strike slows the target hero by 10% for 3 seconds.

Merciless Resolve:
If an enemy is killed while Vendetta is active it's mana cost is refunded and it's cooldown is reset.

Envenom:
Activate to poison an enemy Hero, dealing 209.88 (+4% per level) damage over 10 seconds.

Level 10:

Fan of Knives

Killing Spree

Level 13:

Blood Loss:
Rupture's bleed effect is extended by 2 seconds.

Shadow Dancer:
If an enemy hero hit with Shadow Strike attacks you within 3 seconds you immediately hit them with another Shadow Strike.

Sprint:
Activate to gain 75% Movement Speed for 3 seconds.

Level 16:

Unseen Killer:
Shadow Strike deals an extra 20% damage while Vanish is active, this does not apply to Shadow Dancer.

Flash of Light:
Activating Vanish blinds nearby enemies for 2 seconds.

Armor of Thorns:
Enemy melee attacker have 10% of the damage they deal inflicted back on them.

Level 20:

Venomous Blades:
Fan of Knives poison's all enemies hit, dealing (x) damage over 5 seconds.

Murderous Intent:
The final hit of Killing Spree deals damage equal to the previous 6 hits.

Found my Target
Deal an extra 40% damage against Illidan.

Rewind:
Activate to reset the cooldowns of your Basic Abilities.

Bolt of the Storm
Activate to teleport to a nearby location.

I wanted to create a female night elf assassin and Maive is the logical candidate. As you can see she is an ambush oriented assassin that excels in picking off lone or weak heroes. She is effective against stealthed opponents due to her trait, but she is also squishy making her vulnerable to other ambushers and gank squads. Ideal rotation would be to mark with Vendetta then attack with Shadow Strike followed by Rupture. Searing Strikes can augment her auto attack for further damage, while Blood for Blood can be use for emergency heals. Vanish can be used as an opener or as an escape tool.

Her Ultimates are situational, Killing Spree offers highest DPS but Fan of Knives will deal more overall damage to a team if both charges hit and Venomous Blades is taken at level 20, and it also gives utility for your team. Plus it is cheaper than Killing Spree, giving it more overall use. Killing Spree will do more damage against a smaller group making it ideal for killing enemies who are away from their groups.

'Found my Target' is an experimental talent that revolves around playing against a characters rival. Having no use if their personal enemy is not present, but offering a slight advantage against that single enemy if they are present. Albeit at the cost of a more general buff.

Personally, I am not sure if such a talent would be welcome or not, I'll leave it to the communities thoughts.

Feel free to offer thought on my creation, I'm always open to suggestions.