For those of you into Comic Books,
Then Green Lantern will be a notable figure, the character Hal Jordan is the first human to take up the mantle as The Green Lantern, The Green Lantern Corps use the power of will, and although to some people this may just be a comic book, I personally think the creator of the Green Lantern was trying to get a point across.

Hear me out on this.

I am a sufferer of both Anxiety and Depression , although the Anxiety is more difficult to manage due to being Autistic (I take Fluoxetine for it) the depression however is much more manageable even without the fluoxetine in my system and this is down to the DC hero the Green Lantern.
I watched the cartoon as a child back when it was on Fox Kids and I ended up with a devoted belief in the sense of will.

Sadly although I cannot will myself some cool gadgets at a thought, there are some stuff that has become helpful, beating back Depression and keeping it at bay is one of those achievements I have come to accomplish using willpower.
It could be the way I see things but since I started in the comic book fashion I will continue. So take the Sinestro Corps in the Green Lantern cartoons, they have a yellow ring which the use fear as a catalyst, to me Depression is just an embodiment of Fear. Yeah sometimes depression can get the best of you where you need a bit of help to fight it back, but if you have a strong sense of will it isn’t going to defeat you.

As the classic saying goes “You have to have the WILL to survive”

So yeah it is a powerful force, I don’t class Will as an emotion, I class it as an internal sense that works alongside your intuition, Belief and self worth.