After testing Discharge for a bit, I found a flaw. If you have a large amount of range, you may be actually reducing the duration of the cc effect. This mainly applies when the tesla coils arc towards each other. By increasing the range, you increase the radius of the teslas' range. If more arcs make contact with each other, then they take more damage, which makes them reach the dmg cap faster and end the cc sooner. Of course, this only applies when the teslas are close enough to each other. When the enemies are alone, the ability is amazing at cc. But, if you want the cc to last as long as possible, negative range would be beneficial in that case, which is pretty much the opposite of every other cc abilities that I know of. Putting in Power Strength also does nothing really to extend the duration of the cc, since it increases both the dmg of the ability and it's dmg cap proportionally. I say either remove the dmg cap, or keep the dmg cap but make the stun duration based on Power Duration only.
How about the ability deals diminishing dmg instead. After dealing about x amount of dmg, the ticks' dmg gets reduced by some sort of percentage, maybe like 50% or something. That way, the ability will still be able to have cc based on duration while also not dealing extreme amounts of dmg.