How to make darkness?

This is a screenshot from Reven game

How can i make the darkness effect

I don't want to use webgl effects, i saw this effect in many C2 game like Our Darker Purpose and reven.

So anyone know the secret will help me alot

2 Options

1- Use layer at top using opacity with black color.

2- Use sprite with transparent edges in bigger radio, you can create a composite scene using by only one sprite.

Thank's Joannesalfa, but i didn't understand your second option.

and i think they used webgl effect for the darkness.

Try this little demo might help you understand

Thank's alot Lordshiva1948 for the example, but i think you should watch reven or our darker video to see the effect in gameplay.

It's a very unique dark effect.

If you can create video then surely you can work this one out. I showed you ease method but, if you ponder on this subject and go through the C2 manual I am sure you will work it out. We are here to show you how to and re4st is up to you ti work it out