Leah by TimeLord

Level 1:
Soul Prison: Increase the maximum number of souls of Soul Trap to 20.
Sharpened Arrows: Enchanted Arrows deal 100% more damage to non-Heroic targets.
Ally in Combat: Killing Minions grants you 1 stack of Bribe per Minion. Use 20 stacks to bribe a Mercenary. Max 80 stacks.

Level 4:
Armor-Piercing Arrows: Quest: Hit 40 enemy Heroes with Enchanted Arrows. Reward: Armor reduction increased to 20.
Enduring Prophecy: Prophecy now reveals enemy Heroes for 3 seconds.
Quick Burst: Each enemy Hero damaged by Burst of Power reduced its cooldown by 1 second.

Level 7:
Soul Heal: Activate Soul Trap to heal for 15% of your maximum Health. Cooldown: 45 seconds.
Mental Energy: Casting Prophecy restores 10% of your maximum Mana, plus 5% for each Hero revealed.
Destructive Arrows: Enchanted Arrows destroy 1 Ammo per arrow.

Level 10:
Unstable Power: Throw out the Black Soulstone at the target location. After 1.5 seconds it explodes, damaging nearby enemies. The damage depends on the number of souls it contains.
Possessed: Increase your maximum health by 50% and replace your basic abilities with Diablo's. Your Heroic Ability becomes Lightning Breath. Lasts 10 seconds.

Level 13:
Shocking Burst: Burst of Power roots enemy Heroes for 0.5 seconds.
Mighty Burst: Increases damage of Burst of Power by 10% for each Hero damaged.
Soul Power: Soul Trap increases your basic ability damage by 1% per soul.

Level 16:
Nightmare: Enemy Heroes revealed by Prophecy are slowed by 20% and have reduced basic ability damage by 30% for the duration of Prophecy.
Cruel Arrows: Attacking Heroes repeatedly with Enchanted Arrows increased the damage of the next Enchanted Arrow by 5%, up to 20%.
Volley: Increases the duration of Enchanted Arrows to 6 seconds.

Level 20:
Unstable Explosion: The Soulstone explosion also Silences enemies for 2 seconds.
Diablo: While in Possessed form, you can also cast Apocalypse. There is a 5 second cooldown between casting Lightning Breath and Apocalypse.
Premonition: Prophecy now reveals all enemy Heroes on the map.