I am average?! I think

A certain old man travels back in time to his younger days.
But with a twist.
The world changed as he traveled.
New childhood,new friends, new love interest/s?
"Why the heck is this happening to me!!!"
Now that young man is running away from monsters and girls?

Fantasy people coming into the modern world.
Wars erupt.
So does our mc as he leads the otherworldly people helping them on adapting to the modern day.
Wars because of power struggle.
Wars start to gain the love of the mc's heart.
magic vs. modern
"Let the journey begin!"