This should be hotfixed.
It doesn't even have to do with Dark Harvest, the problem is that you can no longer shut him down early thanks to the turret changes and he's no longer punished for building glass cannon. He transitions into mid game with enough AP to obliterate all of your carries with a single press and minimal opportunities to prevent it.
meowwow77 voteshow much mr did you or your teammates have?
FOR JUSTICE6 voteshmmm.. a random downvote i see. probably not much then.
Tahminatrix 5 votesIt has long cooldown and its completely countered by so many champs, even a tahm with his W on cd can save someone from it with his R at the cost of only putting a 10 second cd on it.
Modl Ryden l1 votes[{quoted}](name=Super Cow Swag,realm=NA,application-id=3ErqAdtq,discussion-id=hoBj8gLw,comment-id=0001,timestamp=2018-11-25T05:48:56.167+0000)
It has long cooldown and its completely countered by so many champs, even a tahm with his W on cd can save someone from it with his R at the cost of only putting a 10 second cd on it.
There's also the fact that cd modifers like Presence of Mind and Ultimate Hunter Exist. You don't have to get a kill to let the cooldown reset by 10%. Just press R and if your team manages to ace then it's reset 50% of the ulti.
Tahminatrix 1 votesIf your team manages to get an ace then the enemy has lost either from pure outscale or the enemy just doing horribly bad.
DuskDaUmbreon3 votesIt's balanced out by being incredibly telegraphed, and with assloads of things to negate it.
Unfortunately without a rework Riot can't really change it...
Rester2 votesIf AP 
If AD 
There's your counter.
Mordepool2 votes
Build to counter then
The entire team1 votes
ApexInTheCircle1 votesKarthus has never been a problem nor will he be, the main issue is dark harvest and how easily he can stack it.
