Premise[]
If you read my Warcraft feat blog (probably not), you'd know Malygos had the feat of creating the Nexus, which moved high volumes of magic onto leylines, and began literally splintering the crust of the Earth.
We're going to try to calc it.
Calc[]
So, we need to know Frag and V. Frag for the Earth's crust. We will use this as a source to help us find these values.
Based on that, the MPa of a material can be directly converted to j/cc for fragmenting it. MPa of the crust is 300-700 MPa, for an average of 500 j/cc for fragmentation (good lord). That said, I can't seem to find suggested values for V. Frag (compressive strength).
Now then, volume of area being destroyed. The crust is 30 km in thickness, and extends across the world's surface (duh). World has a surface area of 510.1 trillion m^2, or 5.101e18 cm^2. Multiply by 3000000 cm thickness to get total volume of 1.5303e25 cm^3. Multiply by our newfound value for fragmentation to get a low-balled result of 7.652e27 Joules, or Multi-Continent level. But we're not done.
This was not done instantly. We don't have timeframe, but we do know that this was relatively urgent at the time it began doing the damage, so let's say 24 hours. This seems fair purely because even though this event can take literally months in game time depending on how long you drag your feet, it has no set time. A day seems fine.
Divide by, say, 17280 to get AP, then. 5 seconds for a charged power seems like a good amount of time for mundane AP. This nets us 4.428e23 Joules, 105.83 Teratons of TNT, Large Country level.
Adequate lowball. As a high-ball, we'll say it takes less time. Why can we assume this? Well, when our heroes attack, the damage hasn't even started happening. Considering they had to go quickly to avert it, seems possible that the attack could have done it in a timeframe as low as an hour. Really, either end is as likely.
Doing the same thing for our new timeframe, our attack comes out to 1.063e25, 2.54 Petatons of TNT, Continent level+. Considering the implications of urgency, I'm more inclined to go with this end since both are hypotheticals.
Tallies[]
Malygos Splinters the Crust (Low-End): 105.83 Teratons of TNT, Large Country level
Malygos Splinters the Crust (High-End): 2.54 Petatons of TNT, Continent level+
Considering Deathwing was significantly superior to Malygos in power, I'd say he should be High 6-A.