Maxed lightening tower rune will give 10% increase to main feature and only 5% to secondary feature.
I believe this is disappointing and needs adjustment!
For prospective, a mythic rune will give 5% boost for both AP+HP. CONSIDERING ASSOCIATED COST OF RUNE DUST AND SIGIL, it has be better
Could you replace Secondary feature to something like SuperShot boost or speed?
Or perhaps, make Both boosts at 10%.