Shadowbolt

Overview
Using this ability will heavily slow your character for the duration of the cast time, during this period ability can be canceled. After cast time is complete without interruption, projectile will be released from position of your character in the direction of your cursor. After hitting enemy unit projectile will disappear, deal 180% magic damage to target unit and apply  Leech . Hitting objects will also destroy projectile and deal damage to object hit, if possible.

After Gloomrot update, the magic damage was reduced from 200% to 180%.

Strategy
Shadowbolt is spell with heavy damage, but long cast time makes you vulnerable to enemy spells and long cooldown makes missing this ability devastating. This ability is great when combined with some kind of disable, like stun from, incapacitate from Slashers' Camouflage or heavy snare, if you know that enemy already used their defensive abilities.

Video Showcase
Теневой болт