Good concept. The black outline around the explosion detracts from the impact of the image IMHO. It should be a glow.
Try to fix your link so it leads to the brush or brushes actually used.

Story:
"The old man was looking through the window and he was seeing..nothing, cause he was already blinded by the flash explosion a few seconds ago."
Imo, windows would be broken from the exp. at that range - but anyways, i like the concept- imagine staring at an incoming tsunami.

agrees to greyval.. hahaha lol

very very nice work author...reminds me on inevitable...Val's plot gives depth to your creation author...best of luck

It's a creepy story... and mankind is not far from there if we continue acting against life.

Looks like you color inverted the window part ?
Hmm not sure if it helps the image but anyway good luck !