As we do not know the name of the "avatar" in Sonic forces, we shall call them Rookie. BTW, I do not own Sonic... Yet.
The attack had come like a whirlwind. Rookie was just hanging out with her/his friends, when suddenly a noise came from the square. The three animals ran to the town square, shocked at what they saw.
Some sort of hedgehog/mecha was attacking the townspeople. Rookie saw her/his father with some other people shooting laser guns at the mecha hedgehog. The weird stranger dodged these with ease, then disentergrated several of the Resistance people. Excluding Rookie's father and some other guy.
Rookie's friends at once ran forward and took up the laser guns. The five fighting, plus Rookie, were the only people left in the town who were alive.
The hedgehog/mecha laughed and said, "Do you really think those little guns can stop me?" He summoned a ball of dark red energy.
Rookie attempted to yell a warning, but it was too late.
The ball of energy was sent at her father, friends, and the other guy. They disentergrated. Rookie ran forward and grabbed one of the guns and pointed it at the enemy, his/her hand shaking.
He laughed, "Poor, fearful child." He used some more energy to knock the gun out of his/her hand. Rookie fell back, trembling.
"Flee, screaming, and I will let you live, child. Flee like the few sensible ones left alive, or follow the same fate as these fools." He gestured at the piles of dust. Rookie did not run, she/he was in shock. The hedgehog-mecha laughed.