Something for Rod of Ages at Level 18?
NEW UNIQUE PASSIVE - RESURGENCE: Enabled upon reaching Level 18. Siege minions or large monsters that you or nearby allies kill restore health and mana to you over several seconds. Additional kills refresh the duration but do not stack.
It's a late game item, yet a part of its functionality becomes redundant once you reach the late game. Maybe have something like this? I don't know. Just strikes me as odd. And yes, I did steal this from that upcoming Strength of Ages keystone mastery in the Preseason; shamelessly, I might add.