Feat's here. Enemies exploding on death as per one of the main character's perks. Enemies often tank these levels of explosions while taking damage without dying.
Player character's measured at 216 pixels (I lowballed the measurement due to his feet being angled due to flying, this should approximate his height if he was standing normally). Average human male is around 177cm, so 0.8194cm/pixel.
A diameter of 464 pixels means a radius of 232 pixels, or 190.11 cm, or 1.9011 m.
Using the equation for non-nuclear yield in grams of TNT Y = ((x/0.28)^3)/2, Y = ((1.9011/0.28)^3)/2 gives 156.4987 grams of TNT, or 654,790 joules, 43.65x baseline Wall level, 9-B