You were sent out by the Resistance to Angel Island to do some scouting and recon work. Angel Island was currently under the control of an Executioner, aka an exe, called Satanos. The origin of these eternal nightmares that have befallen Mobius, Satanos has made himself at home on Angel Island, and is presumably using the endless power of the Master Emerald to power himself up and keep control of a large majority of Mobius not already taken over by other exes.
As you sat from above on a cliff, you looked down at the once beautiful land of Angel Island. The island once floated in the sky, but Satanos's abuse and corruption of the Master Emerald has destabilized it, causing it to fall down to Mobius, where it has now sat in the middle of the ocean for the past five years.
Looking around, you could see a gorey but intentional display of macabre decoration. Flickies were nailed to crudely made wooden crosses, their stomachs cut open so their innards could spill out in a display of cruel sadism. All their eyes were also removed. A wooden sign read "SEE NO EVIL".
The grass was a dull, pale dark gray, and the trees drooped like long necks, drained of life and sstenance.
The Master Emerald's shrine, too, was in ruin, with stone pillars left in rubble, and the emerald itself nowhere to be found, likely relocated by Satanos.
You take the risk to move forward, but just as you do, you hear disorder, glitched, sinister laughter from behind you. You turn to see the being himself. The fallen angel. The reject of the Father. Satanos, in a psychotic version of Sonic the Hedgehog's body. His head twitched violently and erratically, snapping every which way like an asset that was colliding and clipping into another object. His head snapped upside down, sideways, and every other which way, before snapping still as he stared at you with a wide grin on his muzzle, his white gloved hands clenched into fists.
"LOST LITTLE LAMB. YOU DO NOT BELONG HERE. BUT THE DEVIL IS KIND; THE DEVIL WANTS TO HELP YOU. BEND YOUR KNEES TO THE GROUND, AND FALL. FALL AND WEEP BEFORE ME."
In the blink of an eye, Satanos ran towards you with speed matching Sonic's, ready to strike. Thankfully, you wouldn't be a Resistance member if you were weak, so you manage to actually catch and clash arms with Satanos, now locked in a struggle with the Devil.
"STRONG LAMB. STRONG, STRONG LAMB. SUCH A WASTE." Satanos's red shoes firmly planted in the ground, he pushes against you with his arm, looking deep into your eyes with extremely tiny pupils. "BUT SUCH EFFORT WILL SURELY GO TO WASTE. YOU WOULD HAVE SERVED FINELY IN AN ARMY AMONGST MY OWN, WHERE A TRULY GLORIOUS CAUSE BATHED IN BRIMSTONE AWAITED YOU. BUT I SUPPOSE I SHAN'T BE SURPRISED. ALL THE FATHER'S CREATIONS ARE LITTLE MORE THAN HEATHENS."