Hall of Blades needs resets to be relevant
Keystone resets on enemy champion takedown
I don't see how attack speed like Hail of Blades will be a good or even desirable keystone. It offers attack speed but for only 3 auto attacks where Lethal Tempo offer attack speed or 6 seconds.
Another issue that HoB is not picked is that lategame people teamfight all the time and attack speed for 3 auto attacks doesn't do anything as you have to stop attacking for long period of time that you don't have in teamfights. Lethal Thempo last 6 seconds which may do alot then it goes on 6 seconds cooldown and is available again for use.
Attack speed without damage will do nothing so either you need to give it resets or you need to give it some sort of damage to be useful
Another thing it comes to my mind is that Press the Attack and Electrocute are probably too similar to each other
faster. Not even a good burst rune when there are far better options if you want that. It can be fairly good on some champs early/laning phase though.