Aftershock is the easiest attack to dodge in the entire game, barring charge and maybe abduction. If you seriously need slows to keep it down, something’s not right. Not to mention that while it might not be affected by slows it’s movement speed is halved during the attack.
Lightning Strike on the ground denies any movement at all and in the air it’s so minor that I can’t believe it’s being noticed.
I might be completely wrong, but I think Macman or any of the devs would agree right now with telemetry that no one ever uses Aftershock but a few people like me. I tied -and failed- to convince @MaddCow the other day that it’s actually useful. Granted, I think Banshee Mines are completely useless and he parades them about like the best thing since sliced bread, but he’s the hyper competitive monster player.
If the fantastic competitive monster player who knows Kraken better than his own back hand thinks aftershock needs a buff to even be viable, I think this conversation is a bit one sided.