Just remove Conqueror and Dark Harvest, these 2 runes brought anything but negative gameplay...
It's only fair that these keystone should be removed since the other 3 runes don't have 4 keystones. Dark harvest when it was reworked what a huge balance fest and had to be hotfix twice until 1 champion in particular was able to use it efficiently. cough cough Karthus cough And Literally became an ARAM made only keystone.
When Conqueror was release every tanks winrate plummeted downward and was forced to receives numerous damages buffs to compensate for the keystones. True damage is just too strong of a stat when given to every single melee champions in the game. It made Bruisers extremely strong against Tank and made Juggernaut extremely obsolete. Why pick a Juggernaut when you can play a Bruisers and do the same thing they do by being unkillable and have high mobility and attack rate.
will require compensation buffs for the removal of Conqueror, since it is the only viable rune on him.
will require compensation buffs for the removal of Dark Harvest, since it is the only viable on him.
and
because it is easy to get stacks and kill the target.