I feel I am relatively well versed in this game. I use d3planner and everything while am on the leaderboards. Yet I cannot for the life of me figure out why the cold wave of light (shattering light) rune hits for jack squat most of the time. According to d3planner both the initial cold bell and the wave should be hitting for the same as the fire rune. However, when put into practice that's clearly not the case (hitting for roughly 1/2 to 1/3 most of the time of the fire runes damage) and I cannot figure out why. A enemy inside the initial cold bell attack should also be getting hit by the wave and everything in a line behind the bell. This does seem to work properly but the numbers aren't there. technically a enemy should die twice as quickly with the cold rune since you hit twice and fire only hits once while both SHOULD be putting out the same amount of damage per hit. Furthermore, the fire rune does more damage than all of the runes per target hit. Even more than the holy rune which does 1045% damage. There is simply something wrong with the numbers. I've also removed elemental damage from the equation and numbers just don't add up!
I completely agree with this post. I'm getting to that point in the season where I have most of the gear, stats, and levels for higher tier GRs so I'm tinkering with the build trying out different runes outside of the cookie cutter.
I tried the holy rune last night and was hitting for jack squat @ 100 200 billion damage crits, whereas with the fire rune, I can nearly one shot the entire screen @ 500 - 800 billion crits.
It's sort of a simple answer. The difference is AoE damage versus single target damage. While Shattering Light does single target damage in a line, Explosive Light does AoE damage to all enemies around your target.
You're probably missing the main part. The attack stops at your target. It's not an AoE rune. So when you kill the FIRST target, it goes to the next target after your FIRST target. Just because the rune says "line" doesn't mean it does the same damage in that line. It just means that the attack goes in a line but stops at the first target you hit and continues after you kill that target.
I think it would have been specified if so... "Wave of Light does an additional 820% weapon damage as Cold in a line".... to all nearby enemies or pierces through enemies. But it doesn't say that. Surrounding enemies aren't affected by this. That's why you'll notice that you'll have to aim exactly at your target in order to kill it.