Lyndon by TimeLord

Level 1:
Slowing Shot: Quest: Hit 50 Heroes with basic attacks. Reward: Increase the slow of Crippling Shot to 30%.
Venomous Bolts: Quest: Hit 50 Heroes with basic attacks. Reward: Increase the poison damage of Poison Bolts.
Seasoned Marksman

Level 4:
Eat Dust: Increases the size of the cloud of dust by 30%.
Improved Formula: Poison Bolts deal 100% more damage to Minions, Mercenaries and Monsters.
Spare Medicine: Increases the healing of Hysteria to 35% of the damage dealt.

Level 7:
Blinding Powder: Dirty Fighting now blinds enemies for 2.5 seconds.
Frenzy: Attacking enemies during Hysteria increases your attack speed by 5% per attack, up to 20%. The bonus lasts 4 seconds.
Combo Hit: Hitting an enemy damaged by Poison Bolts with Crippling Shot slows them for 3 seconds instead of 1.5.

Level 10:
Anatomy: Your basic attacks seek out nearby enemy Heroes with the lowest health, dealing 40% bonus damage. Lasts 7 seconds.
Powered Shot: Fire an arrow that attaches to the first enemy hit and explodes after 1.5 seconds, damaging and stunning all nearby enemies for 2 seconds.

Level 13:
Quick Escape: Increases the movement speed bonus of Dirty Fighting to 35%.
Master Marksman: Triple Shot bolts travel 20% faster, and deal 10% more damage for each enemy Hero hit.
Toxic Fumes: Casting Dirty Fighting on enemies affected by Poison Bolts increases the poison damage by 20%.

Level 16:
Penta Shot: Triple Shot now fires 5 bolts instead of 3.
Double Triple: Triple Shot gains 2 charges, and the bolts travel 30% faster.
Chaotic: Increases the duration of Hysteria to 5 seconds and the bonus damage to 40%.

Level 20:
Vicious Attack: Increases the bonus damage of Anatomy to 50%. Basic attacks refresh its duration.
Explosive Shot: Powered Shot now explodes after 1 second and deals 30% more damage.
Double Efficiency: Your basic attacks now gain bonuses from Crippling Shot and Poison Bolts at the same time.