Better for Assassination Cold Blood macro: Envenom or Kingsbane?

I’m a pretty casual player who rarely ventures beyond Heroic raiding, so I don’t really care about min/maxxing and try to use as many macros as possible to make things easier.

What would be the better option to macro Cold Blood to, Envenom or Kingsbane?

kingsbane for sure

Envenom, it does almost as much as the initial damage of Kingsbane but you’ll actually use Cold Blood nearly on cooldown. If it was on Kingsbane, you’d be holding it off cooldown for at least 15 seconds every time.

Assassination doesn’t really make good use of Cold Blood in general however, it doesn’t have any really big hitting single attacks worth ensuring a crit. By my mental napkin math it’d contribute like less than 0.1% to your damage.

I paired the skill with Rupture and it also had a decent effect. It doesn’t seem like it would but my dummy damage was higher. It was odd