I'm just playing around with the idea. To me Scourge needs to function in a way that actually makes sense. Right now it's basically an overkill button for anything less than a boss. What's the point of exposing an enemies weakness when they're already begging for mercy?
The stacking counter doesn't need to pile on the damage. I was more thinking something like 5 stacks giving +30% damage vs minions, +25% vs Lts and +20% vs Bosses and up on the hit that consumes the stack. It could even be tweaked down fairly easy since it would be overpowered if it were to equal even 150% damage every fifth hit landed. It's not meant to be a crititcal hit method for Corrupters or to trivialize hard targets.