I can’t wrap my head around how a 542 average damage weapon can lead to hits that scale to the trillions. It almost feels like the [ x] multipliers are exponents instead of % multipliers.
Take a 50% [ x] multiplier for the sake of simplicity, does it get multiplied as *1.5 or *X^1.5 or *50?
Because there is no means of obtaining figures into trillions if these percentages were actually multiplied as decimals (*1.5 in the above example for 50% dmg multiplier)
The formula is Blizzard didn’t bother to test the new class before they implemented it.
Among other things it has to do Viscous shield being bugged. The numbers that are being generated are not supposed to be happen.
That still doesn’t explain how every class can hit into 100s of millions or billions with a dozen or so small 10-150% [ x] multipliers. Going from 10,000 damage to 100,000,000 is a 10,000 fold increase. For reference, 12 100% [ x] multipliers would result in a multiplicative value of 4096 (2^12). Most multiplier values are not anywhere near 100%.
My strength increases my skill damage by 264%. Then there are all the other damage additive increases and multipliers thrown into the bucket at whatever %'s they are.
Maybe the confusion is the damage comes from the damage in the tooltip of the skill not the weapon damage. My core skill says it does 95,945 damage per hit. My weapon only says 700 whatever.
264% is 3.64x
Yes, and you crit/overpower for how much on mobs?
IMO, the trillion damage is entirely achievable:
Damage x % In Paragon x % In Items x % In Unique effect/Aspects
This season SpiritBorn can reach above 28000% Critical Strike Damge… 
Anywhere from 100 mill to 1 bill +
My overpower damage is 4573% and my crit damage is 3062% are you factoring those numbers and others like vulnerable into your equations?
There’s also the fact overpower damage is based on maximum life and fortify amount.
There are damage % bonuses from passive skills as well as skills like warcry and wrath of the berserker.
And there are multiplicative damage bonuses from glyphs past legendary level.
Crit and overpower are both conditional additive multipliers. Just like venerable. Crit and overpower have baseline 50% [ x] multipliers, 20% for venerable.
Your crit overpowers are (your other additive multipliers + 30.62 + 45.73) * 1.5 *.15 * (multiplicative sum of global multipliers, this calculation is the focal point of this discussion)
that’s adding 280 to the additive multiplier.
There are also things like multiplicative overpower and crit damage on some unique and mythic items.
if you are using the Grandfather, that crit multiplier becomes 50% [ x] * 100 [ x] = *1.5 *2.0 = *3.0 (instead of 2.5 because its multiplicative, assuming these multipliers work like math suggests they should)
Should similar with Banish Lords.
In case you still wondering…
Aspect of unyielding hits…