Shyvana gains stacks when slaying large and epic monsters, as well as champions. Dragons grant extra stacks. Every 100 stack enhances one of Shyvana's abilities. Slaying a Large Monster grants 8 stacks of Draconic Bloodline.
Champion takedowns or slaying the Rift Herald or Baron Nashor grants 15 stacks of Draconic Bloodline.
Slaying a Dragon grants 35 Draconic Bloodline.
Every 100 stacks of Draconic Bloodline enhances one of Shyvana's abilities.
