Pseudo-Fantasy Rising

The world was at peace, peace was of the lands through the meadows and into the valleys.
Up until the Rift has formed above the sky in 2027, Which has fully taken over 1/3 of the world.
Monsters spread from the Rift, and fall onto the lands of humanity and animals alike.
Humanity has turned to desperate measures, separated themselves from each other to build their own capitals and colonies.

They discovered a crystal which gave everyone powers called Affinities. These Affinities can only be used when the person has enough Crystal Power called "Mana"

What will these 7 Kids do to save what is left of Humanity.