Doom Slayer was at ground zero when the Argent Tower unstably opened up the rift to Hell in a big explosion:
This is impressive due to how much energy argent energy could output:
"Argent Energy is produced by neutron activation of Argent plasma, a new and powerful substance that was discovered on Mars. This produces an exothermic reaction where recorded temperatures within the plasma have exceeded previously accepted theoretical limits. Through a process not yet fully understood, Argent plasma remains stable and self-contained throughout. Conventional nuclear power is obsolete. What used to take a nuclear reactor 12 months to produce can be generated in a few seconds by the Argent Tower and packaged into an Argent Accumulator no larger than Samuel Hayden's hand."
~Doom 2016 Codex
This takes place in the future, so we can assume the nuclear reactors by then are way more powerful. I will assume it is at least as powerful as the most powerful nuclear reactors today. The current most powerful single reactor on Earth is the Taishan reactor at 1750 MWh
Taishan 1 is a 1,750MW nuclear reactor which is located within the premises of Taishan Nuclear Power Plant. It is located in Guangdong, China.
www.power-technology.com
1750 megawatt hours is equal to 6,300,000,000,000 joules of energy
A year is 8760 hours
8760 * 6,300,000,000,000 joules = 55.188 petajoules or 13.19 megatons of tnt
In the game you can be any distance from the reactor and it ends the same, so let's assume a distance of at most 5 meters:
Let's assume that, like a nuclear bomb, 50% of the energy is used for the explosion:
55.188 petajoules/0.5 = 27.594 petajoules
At 5 meters, 27.594 petajoules/(4*pi*(5 meters)^2) = 8.783(10)^13 joules per square meter
Doomslayer is 213 centimeters tall
Doomslayer is 163 kilograms, but that’s muscle and human surface area calculations don’t like that, so I will use the ideal weight
This free ideal weight calculator estimates ideal healthy bodyweight based on age, gender, and height based on several popular formulas.
www.calculator.net
At 213 centimeters, I get a weight of 97.3 kilograms
This body surface area calculator estimates the surface area of a person's body based on body weight and height. It compares the results of several formulas.
www.calculator.net
I get 2.13 m^2. Since only either his front or back were facing the explosion I will divide by 2 to get 1.065 m^2
8.783(10)^13 joules per square meter * 1.065 m^2 = 93.539 terajoules or 22.356 kilotons of tnt