So i think the answer is a
War robot or a Mech
It is filled with weapons and we all would like to have one
My functions are complex, I will fight your wars
A war robot is complex and it will fight wars
A design that'll perplex, not bought at your stores.
Its design will be jaw-droppingly awesome
Carefully crafted to be awesome, as I'm stuffed with weapons of war
It is filled with all kinbds of missilkes and bullets
Hear the bullets around you blossom, as the people who use us want more.
Nations will want more of war robots
I fly through the air in a swirl of fire
The war robots, equipped with a rocket will fly around
No tricks are used here, no imaginary wire.
I don't know how the war robots are related to this line
Effort has been taken to make me a reality
It takes a lot of effort to make a war robot
So wait for the great day when you can have one of me.
I would like to have one of them
So the thing is that I came across this new game called 'War Robots' and drew an inspiration from that.