I’m sorry Blizzard, or Kaivax, please please please in the name of who you love transfer this message to the main dev team.
DO NOT TOUCH EXISTING ABILITIES, it will break custom maps, do it like the classic team that used to work, create a NEW item and ability base on Orb of Lightning (New) give the skin for orb of slow and make the ability inside it which is purge into the shadowstrike ability.
And you’re done, DO NOT, AND I REPEAT DO NOT change an existing ability.
The Classic Team did it like pros, check abilities like Ritual Dagger to see the evidence, even with that ability that changed during development they didn’t touch the old ability just made a new one.
For the love of all that is holy dont do this, by Uthers beard dont do this i beg of you, Blizzard, or Kaivax, please make sure the dev team sees this.