Looking on the League of Legends wiki for Shen's Abilities, I was reading Ki Strike and not clear on the wording.
Every 8 seconds, Shen's next attack deals 10 + (5 x level) + (+8% of his bonus health) bonus magic damage. Whenever an enemy champion hits Shen with a basic attack, the cooldown is reduced by 2 seconds.
Specifically I'm unsure about how much damage we're talking about. 10 + 5 x level is easy. But how does "8% of his bonus health" apply? Does it mean 'bonus health' as in the health granted by in-game items/abilities? Does it include things like runes and masteries? Am I misunderstanding this ability completely?