Aftershock should have a lower lv 1 value
The rune gives between 70-120 armor and MR.
The 50 increase from lv 1 to 18 is actually imbalanced. It doesn't keep up with the damage increase in other runes, while at lv 1 it's way too strong.
So i suggest make it range between 40-160. You gain roughly 7 extra stats per level(only 3 now), it's more balanced early and stronger late.