Both thunderlords decree and fervor were so much more healthy than their current counterparts
(being electrocute and conqueror)
I mean, the whole rune + mastery system was a lot more balanced than the mess we have right now where champs have low base armor and mr and almost every rune increases your damage.
I think the best way to start to balance the game is bringing runes back in some form so champs have more defensive stats early on and reverting those keystones.
Crying in
for bringing back Fervor.