Asriel absorbs the Monster Souls / Darksspine

This post was made to determine the power of Asriel when he isn't in his God of Hyperdeath or final forms.

Note that while Asriel did destroy the Barrier, this is likely because he used the Human SOULs to perform that feat. However, again, this is just for base Asriel. Why? For fun.

Prologue
Asriel states that as a flower, he had no SOUL: but after absorbing the monster SOULs, he could feel again, and he could feel them feeling too. What does this mean? It means that Asriel was powered by the monster SOULs and not the Human SOULs in his base form. 

We need to find out the power of a monster soul, and how many he had powering him.

A Single Monster Soul
(Only fodder monsters and low-determination Frisk will be used for this calc. Consider it a lowball.)

Even the weakest of monsters (aka Sans) can harm Frisk with their attacks Frisk can survive the explosion of a MTT brand oven as seen here, which sets Undyne's house on fire afterwards. This is a Building level feat.

That, and the MTT brand ovens can reach tempatures up to 9,000 degrees Fahrenheit, which rivals the heat of the outside of the sun. This means that at their lowest, Frisk can tank a Building level explosion.

And, since the weakest of monsters can always damage Frisk, this means that even the fodder of Undertale are Building level, and can, at their lowest, output .25 tons of tnt. 

How many souls?
Now that we have determined the level of the fodder, we have to find out how many monsters are in the underground. Here we see that the underground is becoming overpopulated and suffers from crowding. This suggests there's more monsters than we find on the overworld in-game. And here we see a vast amount of ratings: specifically 12,165. If we suggest that each one of these is given by a fodder monster and none of the higher tiers, then...

.25 x 12,165 = 3,041.25 tons is the absolute minimum output base Asriel can make. This is excluding higher tier monsters, and a higher-end of tons of tnt, instead choosing the absolute lowest end.

8-A, City Superblock level.