Soul Harvest

Soul Harvest takes souls that fall from enemies attacked by you. Consumes 2 soul energy. When attacking enemy, has a certain chance to gain 1 soul energy in the duration.
 * [Level 1]: harvest chance: 15% / last 90 seconds
 * [Level 2]: harvest chance: 20% / last 120 seconds
 * [Level 3]: harvest chance: 25% / last 150 seconds
 * [Level 4]: harvest chance: 30% / last 180 seconds
 * [Level 5]: harvest chance: 35% / last 210 seconds